You can't just take gear and NOT supplement (or even get your quote of) protein (my mistake back in the day). You simply won't maintain any solid mass. Proper nutrition, as i'm sure most gym rats would agree IS the key to a good, healthy physique. Gear adds size, helps with cuts etc.
I'm not dead set against steroids, each to their own, i just don't think that anyone has an excuse for taking them unless they're competing.
But here are also other reasons for taking them; for me, i was a total hard gainer. 4500kcals/days and still couldn't gain much weight. BF was approx. 10% on a 12st 8lb frame. I used them once, and it honestly seemed to kickstart my metabolism into gaining weight. Never used em again, but learned (and gained) from the experience.