That's the unfortunate reality though, regardless of the medium. McDonalds will always make more money than the local burger shop. Michael Bay flicks will always make more money than a risk-taking indie film. And pop artists will always sell the most records, garner the larger fanbases and gain the most exposure. It's always been like this and probably always will. McDonalds is honestly a perfect comparison to pop music. It's cheap and potentially articficial but does it's job (and is infinitely better when you're drunk); however nobody wants to be that guy that only eats at McDonalds. Music is unfortunately a business like everything else, and artists like Ke$ha, for better or worse, are more marketable. The best thing you could do is concentrate on the artists you love, do everything you can to make sure they keep making music, and let the kids like whatevers on the radio; they'll broaded their horizons eventually *knocks on wood*
I wholeheartedly agree with you although we must be careful to not speak in absolutes here. Are you familiar with popular music from the 70's? That era would like a word with your hypothesis if youre concerned with marketability. Actually every decades popular music up until after the 70's has been resoundingly acceptable to all demographics. Yes, the times are changing and music is becoming more streamlined.
For the record I personally am not the one calling Kesha untalented in here.