Well, I don't really agree that the people fronting uninteresting music groups are talentless, just because we may connect them with music we don't respect.
Personally, I have done some work which I don't think was particularly good, as it is what my job required of me, and it helped the company I work for in some way, and allowed me to feed my family.
It's just business.
Also, I think there is often some fantastic work put into commercial, derivative, or regurgitated music. The products will sometimes have some truly wonderful qualities, though it may not be the musicality.
There are many musicians working professionally, producing sound and music for various commercial endeavours. This is much like visual artists working under patronage, or doing jobs on commission. There was certainly a lot of art of the classical world produced in this way, as it is today. There are still some fine points to be appreciated in commercial endeavours of this kind, provided one understands them for what they are.
As for musicians getting breaks for their own work, I suspect it is now as it has always been. It is hard to sell something truly novel, and most people don't really have an interest in music. However, there is much greater potential for musicians to at least be heard, due to internetworking. In my experience, underground radio stations love to have submissions from unsigned musicians.
I am also pretty sure that music has always had a strong element of re-use of past or other people's material. I think folk music has always had renditions and adaptations. Classical music has had many examples of meddlies, tributes, renditions, and arrangements also. This is stretching back a little to my classical training, but I seem to recall playing scores which were credited as 'arranged by ...' etc. I guess a little digging could find some examples. Certainly I think there are many examples throughout history of composers borrowing ideas. This is often done in a way which produces a valid creative endeavour, though.
Anyway, just some thoughts.