Meh. The rock radio stations are all kind of lame. You've got your '70s leaning classic rock (WMGK), your '80s leaning classic rock (WYSP), your token safe classic rock leaning heritage station (WMMR), and Radio 104.5, which is really more of an Alternative/Hot AC or Alternative/CHR than anything else. 104.5 never bills itself as Alternative in their advertising, and they have an extremely tight playllist of music - if you love repetition, I'm telling you, this is your station. Granted, it's not Top 40-level repetition, but they are easily the safest, most repetitive Alternative station I have ever heard. And they have, shall we say, very questionable taste in the music they play.
Radio 104.5 plays: Fall Out Boy, Paramore, Panic! At The Disco, latter-day Goo Goo Dolls, Puddle Of Mudd, Blues Traveler, easy-listening Police songs, etc.
Radio 104.5 doesn't play: I.R.S.-era R.E.M., Depeche Mode (aside from "People Are People" and Violator) Psychedelic Furs, The Smiths (other than "How Soon Is Now?", The Pixies, The Replacements, Bloc Party, Kaiser Chiefs, Arcade Fire, Spoon, etc.
I think this demonstrates what is wrong with the station - that and the fact that their target audience is one that somehow isn't tired of "Smells Like Teen Spirit", "Under The Bridge", and "Lightning Crashes" yet.
I'll give the station this much - up to this point, they have been successful. But it's just a matter of time before people tire of their ridiculously safe approach to the Alternative format. Also, if they ever got some competition, it would definitely have an impact. The combination of very timid programming with little to no talk means that they don't have much of a hook. Give Philadelphia a somewhat more adventuurous approach to the format with some talk, and the listeners will follow.