Singular "they" is incredibly widely adopted and would be and is easily understood by 1000 of 1000 native English speakers, and would be and has been understood by them for centuries: as the Wikipedia article (directly linked to by yours) says, "the singular they had emerged by the mid-14th century and is common in everyday spoken English". If we've been able to deal with this supposed combinatorial ambiguity for ~700 years, how bad could it be? If we can deal with singular and plural "you", why not singular and plural "they"?
It's certainly not common, even amongst "PC" types or whatever, to want to eliminate gendered pronouns entirely; just that everyone gets to be called the pronoun of their choice (regardless of whatever genitals they were born with), and when the antecedent is of indeterminate gender, a pronoun of indeterminate or at least not a male-default gender is chosen. So Alice and Bob can still be "she" and "he" respectively if they so choose, and there's no confusion there; "they" still refers to both of them. But when a person wants to tell the story of Alice and Bob, that person is "they" or maybe "she" or sometimes "he" - just not "he" by default.
Anyway, slicing up our pronoun space into male/female is entirely arbitrary. Perhaps Alice and Bob are the people chosen for these kinds of stories because our pronouns are gendered; if our language categorized people in different ways than gender, we would chose people as examples along those lines instead. And what do we do when we have a story about Adam and Bob? They're both "he"! How ever do we deal with the combinatorial explosion of ambiguity? And yet people somehow have managed to tell stories with multiple men in them for millennia...
Suppose Adam is tall and Bob is short. Maybe English ought to have different pronouns for men of different heights (or hair colour, or...). It would help relieve this terrible ambiguity here. And yet we get by without this precision in our pronouns.
Perhaps Adam is black and Bob white. Should they have different pronouns to distinguish them? If you say no to that and feel like that maybe might even kind of be a bad idea because of the rigid line it draws between two people created equal, well, now you know why people might be opposed to gendered pronouns.
Some languages have the notion of politeness encoded in, which can often help distinguish pronouns in stories between children and adults, or royalty and their subjects. English doesn't really have this (at least not at a grammatical level), and yet somehow I don't feel my language to be particularly enfeebled without them - I can tell stories about little girls talking to their mothers, or male peasants talking to kings, just fine.
Singular general-neutral "they" has been indeed been around for centuries, but my impression is that its use to refer to specific, named, individuals is novel (e.g. "Please ask Bob what they want for lunch", meaning what Bob the individual wants for lunch). I will admit it feels a little cumbersome to me, but I'll deal. It's a logical way for English to evolve, and fills some genuine needs in the language.
And as with "you", I suspect that if "they"'s use as a gender-neutral pronoun expands, "they all" will soon emerge as an (unofficial?) replacement for the plural.
"Suppose Adam is tall and Bob is short. Maybe English ought to have different pronouns for men of different heights (or hair colour, or...). It would help relieve this terrible ambiguity here. And yet we get by without this precision in our pronouns"
Hm... Let me hijack the current state of languages the other way around: why would we have distinctions at all? Why would we need to express distinctively about animate and inanimate, or about the existing number of colors (when the entire spectrum can be botched to fewer hue names), or to make a distinction between single and non-single (English "you" FYI), or a lot of other stupid differences that force us to think about when we're communicating? Why wouldn't we drop them and market this as a feature, emphasizing the fact that we can speak that way "just fine"? Actually, you know what? Why wouldn't we drop communication entirely?! That would be a wonderful final goal, wouldn't it? I may sound like trolling, but it's important to see the whole picture - the goal of the communicating act in its essence is to transmit perceived distinctions. Now, we can shape the language used for this communication by pushing it either in one direction - of evolution (by gaining the ability to make even more distinctions), which is an open end indeed and that may seem overwhelming, or in the other direction - involution, which (hey, good for us -) has only so much to be reduced to!
Science (including the part addressing languages) is a bitch, isn't it? We have one less linguistic aspect available for politics now!
It's certainly not common, even amongst "PC" types or whatever, to want to eliminate gendered pronouns entirely; just that everyone gets to be called the pronoun of their choice (regardless of whatever genitals they were born with), and when the antecedent is of indeterminate gender, a pronoun of indeterminate or at least not a male-default gender is chosen. So Alice and Bob can still be "she" and "he" respectively if they so choose, and there's no confusion there; "they" still refers to both of them. But when a person wants to tell the story of Alice and Bob, that person is "they" or maybe "she" or sometimes "he" - just not "he" by default.
Anyway, slicing up our pronoun space into male/female is entirely arbitrary. Perhaps Alice and Bob are the people chosen for these kinds of stories because our pronouns are gendered; if our language categorized people in different ways than gender, we would chose people as examples along those lines instead. And what do we do when we have a story about Adam and Bob? They're both "he"! How ever do we deal with the combinatorial explosion of ambiguity? And yet people somehow have managed to tell stories with multiple men in them for millennia...
Suppose Adam is tall and Bob is short. Maybe English ought to have different pronouns for men of different heights (or hair colour, or...). It would help relieve this terrible ambiguity here. And yet we get by without this precision in our pronouns.
Perhaps Adam is black and Bob white. Should they have different pronouns to distinguish them? If you say no to that and feel like that maybe might even kind of be a bad idea because of the rigid line it draws between two people created equal, well, now you know why people might be opposed to gendered pronouns.
Some languages have the notion of politeness encoded in, which can often help distinguish pronouns in stories between children and adults, or royalty and their subjects. English doesn't really have this (at least not at a grammatical level), and yet somehow I don't feel my language to be particularly enfeebled without them - I can tell stories about little girls talking to their mothers, or male peasants talking to kings, just fine.