Short of actually committing a crime, shagging your brother's wife continously for 8 or so years is one of the more fecked up things a high-profile footballer has done in recent times. It hasn't been blown out of proportion at all; most people just find a man like Giggs and what he's done very, very distasteful.
Similarly, the players are going to find what he did distasteful, and no matter how hard they try to seperate Giggs the manager and Giggs the man, it'll always be in the back of their mind somewhere. It's near-impossible to completely ignore something like that.