I don't disagree that it's impossible to get into the same physical shape as Marquez, certainly aesthetically speaking.
But when you're 39 years old, past your physical prime, producing far less testosterone than when you were younger and trying to fight at least 10lbs above your natural weight class (when you struggled at your previous attempt) and then you hire one of the leading PED experts and dealers of the modern athletic era into your training camp, people are going to raise eyebrows.
Then take into account that since hiring Angel Heredia (a guy whose identity they tried to hide until it was revealed by HBO/Victor Conte) Marquez has been looking like a tank of a welterweight.
Some people seem to expect that if someone is on PEDS then they should look superhuman (not saying you believe this, McGrain). That's kind of missing the point, which is that they're not a miracle drug, but they'll be very effective in helping a 39 year old man get in great physical shape and perhaps slow down or turn back the clock a couple of years - have more energy for training, recover quicker, build muscle mass easier, burn off excess fat etc etc.