Here's the problem with skill bars: Bjarne Stroustrup rates himself at 7/10 for C++ knowledge. So if the language creator is at 7/10, where is anyone but the most skilled programmers? Probably somewhere around the 3 to 4 range tops (and the scale might be logarithmic).

But this is a problem because you won't get any jobs if you say your skill in the language they use is 3/10. And of course you have to compete against people even less skilled than yourself who rate themselves at 9/10.

Maybe the way to solve this is to take the space used for skills and use it to show off your projects. If you're new to a language, your most interesting project will be something small and simple. But for the languages you're most comfortable in, you will likely have built something awesome.