As if rating one's skills in a particular subject with a 1-5 rating under no context bears much meaning... it's so arbitrary as to be insignificant (but it could be a cool concept if not abused). It also depends on one's motivation for representing their skill level; for example, jobseekers probably overestimate their skill levels.
It would be great to have a standardized rating system based on a few different tiers wrt a language/framework/etc.:
1 - Wrote some really basic code in the language
...
5 - Wrote some really, really advanced code in the language
It would be great to have a standardized rating system based on a few different tiers wrt a language/framework/etc.: