Steroids gives the player them more power, but they don't give him abilities he doesn't already have. If a player can't hit a curveball, or a change-up (a la Steve Lake), then taking steroids won't magically change those holes in his hitting. When he does make contact, the ball will go farther and faster, but that's all. Even with these PED's limited effects, they do pose a significant health risk that's been proven through good science. So, are the risks worth the rewards? All of our pro leagues now say no, and that answer is enough for me.
As for the juiced ball theories, I'm sure when MLB changes baseball manufacturers, the ball changes as well despite (maybe because of) MLB's spec's for legal balls. If one reads these specs, they contain considerable amount of wiggle room as to what is defined as a legal ball. Therefore, I'm pretty certain there have been changes to the balls the MLB uses for its games, and the effect was probably profound. Also remember the effect that expansion has had in diluting pitching talent; 1977 is a great example along with 1987 as both years were expansion years. Bad pitching means more home runs hit.
The fact that formerly light hitting, contact hitters suddenly hitting over forty home runs consistently in the 2000's is a sign of PED use, as they would have more power using the drugs. These hitter always made hits before, it's just those hits flew longer distances, hence the increase in home runs. Unfortunately, the powers of MLB decided that having tremendous increases in the number of home runs hit was a good thing, and the rise in attendance, and TV ratings after the MLB strike affirmed that belief. The owners raked in the cash, and never questioned how the players were doing it until recently. The PED ban is being reflected now in the decrease in the numbers of home runs hit these days to early 1980's levels. Is this turn of events a good thing? Only time will tell.
