On Tuesday, when Giants broadcaster Mike Krukow revealed that he is suffering from a debilitating muscle disease, the reaction was immediate. The famously nasty SFGate.com trolls did the right thing for once and took a pass. [...] the space was dominated by good wishes for Krukow and praise for his stepping up and going public. Krukow is clearly beloved in the Bay Area, and he and his broadcast partner, Duane Kuiper, have perfected a folksy, witty style that makes everyone fond of them. Krukow could have gotten defensive and told us his personal life was none of our business, that the intrusive media was prying into areas that should be left alone. There are e-mails from people who have IBM or say their father has it. People sometimes ask me what my e-mail is like. Someone told me once that maintaining a bad reputation is the easiest thing in the world. The harder road is to maintain your cred as a class act.