It'd be nice if startups in general took a step back and toned stuff down. Be ambitious and optimistic without pretending your website and the guy who's going to tweak it are solving Very Hard Problems, changing the world and of course disrupting whatever multi-billion dollar industry.
Those startups are the exception not the rule, if you're the only one saying it you're not really doing it.
I don't disagree with what you're saying, but startups are hard. There's lots of ups and downs and getting people to buy into a vision of the world is a lot more comforting when you're working long days and weekends than thinking "gee I love slight iterations for profitable/quick exits". So while I agree with you, I understand why people do it.
Two thoughts: a lot of startups probably are low key, but you don't hear about them on the media circuit for obvious reasons; also, the process of raising money has a tendency to spiral into hyperbole.
Those startups are the exception not the rule, if you're the only one saying it you're not really doing it.