Wilson explained another theory in one of the Factory Story books. He mentioned it again in 24 Hour Party People, but didn't go into detail. It was all to do with his personal circumstances - marriage, baby, girlfriend and he couldn't see a way out of it all.
This seems to me to be a much more reasonable theory than some rubbish about a young man killing himself for the good of a pop band or a bloody record label.
For everyone who knows someone who does someone like that, there's going to be a different explaination. It's worth bearing in mind the Samaritan's argument: if you can stop someone actually commiting suicide at the point they are about to do it, you will probably stop them all together (apologies if I've got that wrong - from memory only). Suicide is usually a spur of the moment decision rather than something that's planned over time.
This pretty much fucks Wilson's Altruism comment, which I would take with a pinch of salt anyway.