Because they say something meaningful, potentially, namely what you're relatively better or worse at, more or less experienced at. Without committing the sin of telling the world what your objectively absolute rating is in some supposedly global but in actuality undefined frame of reference.
Example: "I'm a 6/10 on Apples and an 8 on Oranges, and Bob over there says he's 9 on Apples and 1 on bananas. Turns out in actuality I'm way better at Apples than Bob, but Bob kicks most people's asses at bananas!"
I disagree, because they're completely arbitrary and a full bar can suggest that you either know everything, or you can't improve any more.
Trying to represent knowledge or skill on a finite scale is a bad idea, I think. If I got this CV in a pile I'd want to see examples to demonstrate that skill in place of this section, not a set of percentages pulled from thin air.
Because they say something meaningful, potentially, namely what you're relatively better or worse at, more or less experienced at. Without committing the sin of telling the world what your objectively absolute rating is in some supposedly global but in actuality undefined frame of reference.
Example: "I'm a 6/10 on Apples and an 8 on Oranges, and Bob over there says he's 9 on Apples and 1 on bananas. Turns out in actuality I'm way better at Apples than Bob, but Bob kicks most people's asses at bananas!"