TIOBE is almost more flawed, since it pretends to be scientific while only querying a bunch of search engines (google, SO, wikipedia) for "<language> programming", which is skewed towards languages that tend to be mentioned with the word, such as http://en.wikipedia.org/wiki/C_(programming_language) , as opposed to languages that have a unique enough name, such as http://en.wikipedia.org/wiki/PHP
Unless I'm wrong: The popularity doesn't mean anything necessarily good. More people are probably asking for help in F# than they are in Ruby (much simpler to comprehend). The results aren't really helpful they just give you back indiscriminating numbers.