OK - I am going to buck the trend here...
-1
Sorry, Joe, but there's a very important point being missed (by many) in just about this entire thread.
A person who defines themselves by the tools they use (original music, cover tunes, guitar, synth, voice) is a tool.
A person who defines themselves by what they do is a person who does stuff.
If you are in the moment and serving the music, it shouldn't matter who wrote it - that's not the point. The point is serving the music for music's sake. Anything else is ego run amok.
In my opinion, if the fact that a song was written by someone else takes away your ability to enjoy playing it, you've seriously limited your opportunities for pleasure as a musician.
Once people buy into the "two different ethos" myth, all the rest is down hill leading you further from the point.
Being a musician is a singular thing. It's not broken down into "cover" vs. "original" vs. "spontaneous" vs. "classical" vs. "jazz" vs. "industrial" vs... Those are boxes. Climb in if you like, I'll stay outside and keep all opportunities for musical satisfaction wide open, thank you!