If by "homegrown" you mean developed by the club (i.e. they played for the club between the ages of say 16 and 18) but regardless of nationality then I totally support that. Of course, I am biased because at Arsenal we have a number of such players and more coming through.
But you can't do it by nationality, not in Europe.
I don't support propping up bad players just because they've got the right passport. Competition is what makes players better. Even David Bentley agrees on that point.
If Arsenal can't field 4 English players in a 18 man squad (don't have to start or play) then we might as well scrap international football in England. I don't agree with Blatter but the clubs need to do more and I can't see why a compromise cannot be achieved.