Because he is a Yankee.
Because people want to see those stars brought down to earth, if you will, can't have someone being all perfect. The same reasons that people were happy when Michael Jordan, Tiger Woods, Kobe Bryant and so on all got into trouble.

While I agree with your sentiment, AROD specifically, DOES very much care what people think, which is why he hired people to lie and say good things about him, carry signs, organize grass roots efforts to clear his name, sued people, on and on and on.

Then when people caught onto the bullshit he finally got wise and stopped.

Carry on.

He cares about how his baseball playing days are regarded by his peers. He will always be looked at as the one that could have, the one that everyone believed in, but yet he was a user. He disgraced his name and his baseball career by cheating. That is what he will always be known as, someone that didn't believe he was good enough without cheating.
That money cannot buy self worth.

Fingers crossed for Miguel Cabrera.