show us any evidence that 10-20 grams of creatine has any effect on building muscle. Sure it pumps you up, but you haven't actually added any muscle mass.
Speak for yourself. Creatine has done right by me (Yes, I have gone periods without using it; and, yes, the size I gained while using it remained).
if any of the supplements available at the health food store were effective, why isn't the average (non-steroided) gym goer any bigger that what they were 20-30 years ago?
You are alleging that, over the last two to three decades, that the only folks who have improved their physiques are steroid users? That makes no sense, whatsoever.
I suppose the minor fact that creatine has been arguably the most popular supplement over the last 10-15 years, with testimonies galore (here and in gyms nationwide) were just for "placebo" purposes.
Furthermore, I thought the supplement for pumps was L-arginine, not creatine (although many NO products have both creatine and L-arginine in them). In any event, the products today are FAR better than they were, when I first started training in the late 80s. Outside of protein powders and carb-heavy weight gainers, the selection was rather meager.
I agree with Lee Priest, when he says that, while he's all for being open about steroid use in bodybuilding, the problem with talking about it so much is that too many people get crippled and think that they can't do jack without drugs. As he puts it,
There are people who climb Mt. Everest with no legs. And you're telling me you can't put 10 lbs. on your bench, unless you pop some D-bol?" (paraphrasing from memory).