maybe so...
although ive seen some tiny tits get huge very very fast by starting cycles. they eat like crap and still were huge.
of course when you see people come off the sauce....you then realize how much drugs played a part in their physique....to say its just the finishing tough seems a little bit of an understatement. no?
They eat like crap and get huge, then lose it. Why? Because they didn't gain quality muscle. They "blew up" with a combo of fat, muscle, and water. If and when they cut down, the muscle they did gain will likely be lost - leaving you to say they were "all drugs."
Finishing touch? Yes, it's an understatement but the role drugs play is difficult to quantify. For instance, a natural BB and a drug-enhanced BB shouldn't train the same way - no way. For instance, a most non-nattys can do fine on a 3 day on - 1 off training split, while I would almost never recommend this to a natty. Their recovery just isn't in the same ballpark. Also, AAS allow your body to synthesize more protein, so a non-natty needs to eat more (clean food) than the natty. Again, does this make them all drugs? Personally, I think not.
Also, you should recognize that people have different responses to gear. Take Dan Duchaine for example. He had all the knowledge and access to revolutionary new BB drugs (for his time) but he was never a good BBer. His response just sucked. He recognized this and wrote about it somewhere.