It is true that it's generally the record companies that are making a big deal over this, so you might have a point. Look, if someone can prove that artists are losing money out of the whole thing then, regardless of anything else, it's a bad thing because musicians have to struggle to support themselves anyway. That whole idea of pirating things you like and therefore not paying for the very things you should be supporting comes into it.
However, without that proof (and I have a sneaking suspicion that it doesn't exist) then one major problem arises for the artists. The only control over songs that an artist has is intellectual copywrite, that they control how it gets distributed. If an artist doesn't have control over their own songs then it is a bit unfair. However, the very concept of artists having control of music, rather than the public in general is a pretty modern idea - in the past the composer was never considered to be special, the music was simply there to serve a purpose. It's a bit shaky ground to argue that it is some irrefutable right for the artist to have control over how their song is distributed, so it can be a bit hard to get upset about programs that attack that control.
On the othe rhand, I never use any file sharing programs, I can't be bothered.