I am conflating Bill and Hillary here, but I've yet to see an argument that their opinions on loyalty differ.
Bill Clinton has campaigned for people who supported Hillary over Obama in 2008.
This is also known as rewarding your supporters.
There were more prominent Dems who didn't run in '92 than did. Of the people who ran, they were either dying (Tsongas), scandal-tainted (Wilder), bitter about losing (Kerrey, Brown) or valuable allies in key Senate seats (Harkin). Not a good group to fill your cabinet. And really, Cuomo and Clinton were at loggerheads for a long time, more so than some of the guys who ran.
That's not really petty; that was an incredibly tacky thing to say in public. If I said, "I don't want my daughter driving home with a Kennedy," I wouldn't expect a Kennedy to campaign with me the following day.