I think a lot of them doped back then. The difference was that the drugs were simpler, and often more in line with amphetamines. This will sounds sort of perverse, but everyone had the same chance since they all had access to pretty much the same drugs, mostly stimulants. Not so, today. Drugs like EPO have totally changed the scene. Designer drugs tailored to individual riders allegedly give some obscene advantages over others.
Also, note that Eddy has admitted that he doped at one or two points, but is adamant that at least one drug test (the Giro affair) was rigged by the Giro organizers. This was immediately after Eddy was allegedly offered a bribe to let a lesser Italian win the Italian national tour. When he refused, presto, his samples came back positive.
I'm not defending doping, just trying to put some perspective on things. Doping back then, while still wrong and a form of cheating, was very different. No one's blood oxygen carrying ability was altered by EPO, for example. And, samples were still liable to mishandling, just as Floyd's were. Now, before you jump on me, I believe Floyd to be a lying, cheating, sleazy, scumbag weasel. However, if his hearing did any good at all, it was in demonstrating that while the proper results came back, the lab doing the work on his samples was slipshod in its methods, at best. That makes me wonder which other cyclists were actually clean but had their samples come back as positive due to lab errors, or even outright manipulation, like Eddy's reportedly were at the Giro.