Do you have any evidence for those claims, or anything resembling those examples?
Music copyright has long expired for classical music, and big shots are definitely not exempt from where it applies. Just look at how much heat Ed Sheeran, one of the biggest contemporary pop stars, got for "stealing" a phrase that was literally just chanting "Oh-I" a few times (just to be clear, I am familiar with the case and find it infuriating that this petty rent-seeking attempt went to trial at all, even if Sheeran ended up being completely cleared, but to great personal distress as he said afterwards).
And who ever got sued for using dev tools? Is there even a way to find that out?