While the abuse button is decidedly intended for abuse (which misplaced threads certainly do not constitute), I don't have a problem with it being used for threads that have clearly been overlooked for a significant amount of time. But since those reports clog our personal email inboxes, they really shouldn't be used for everyday stuff -- save the Report Abuse button for emergencies, like spam or NSFW stuff.
Besides, we are quite diligent about finding misplaced threads. They're seldom around for very long in the wrong place. (I'd think you would have noticed this.)
I think that saying "Move to iMac" is out of line. Though Lateralus's reply was, IMHO, rudely worded, he's basically right: ask or suggest things, but don't just command. We're not your servants, and the decision is ultimately ours, after all.
In this particular case, I don't agree that the Power Mac forum is the wrong place -- the thread really isn't specific to any model, it's a discussion of overall CPU strategy, really. Since the Power Mac is the only model whose future processor isn't clear, the thread is certainly relevant where it is.
tooki