Well in my opinion, given sports where it's rife, it doesn't tend to make champions of people who wouldn't otherwise be champions, all other things being equal - but I'm sure some will dispute that.
It does. Bjarne Riis used to get spanked out of the back of the peloton on hills as steep as a motorway flyover on a regular basis, a handful of months later hes climbing with the best of the non-specialists in the world in the TDF. And then goes on to win.
Some people respond very very very well to EPO and its chums. Some don't. The problem is that all the clinical trials are done to save lives, so the doses used and results obtained can't be scaled up properly to show the effects on healthy (or at least, fit) athletes. So there is no hard and fast method to work out who would win if the drugs were taken out of the equation.
And the Armstrong hate is more down to his methods and the fall out rather than the actual drug use itself, as its been stated before, the vast majority were at it. But they didn't actively set out to ruin anyone who made any sort of suggestion that they were. Neither did they force the rest of their team to dope up (or loose their jobs) to support the TDF dream. (Yes there are some riders who lost their jobs, Obree for one, but its not an entire team driven to dope up to support one rider in winning one race)