It's not really a thing anymore, but in those days so much credibility existed in not being seen as a 'sell out'. Especially if you came up though the alt scenes. But supporting a massive stadium act was exactly that. And signing with Geffen was too. For Faith No More and Nirvana it probably tore them up inside trying to justify those decisions, as well as being big rock stars in their own right. And it really wasn't worth the angst. It's just music. And absolutely no-one cares about whether you sold-out in 2023. Besides, the 'cool' people they were trying to impress back then are probably all CEOs of multinational organisations now...