Because of general spite or because of what he purportedly endured via the hazing? That makes a difference.
In any event, it seems to me that his intent toward Fitz doesn't matter. All that matters is substantiating what occurred, whether it was ongoing and (worse) systematic, and what Fitz's ultimate responsibility for this sort of thing is.
As others have noted, it's normal for nearly all former players to circle the wagons on this. If they didn't directly participate in the brutality (and it actually occurred), they acquiesced to it and have lived in silence about it since. Seems psychologically predictable to attempt to kill the messenger who reminds you that you stood by time and again, said/did nothing, and have maintained that status quo, perhaps for a decade or more.
"He's a bitter malcontent" is a quick, cowardly way of marginalizing someone who breaks a conspiracy of silence concerning something shameful.