I don't think Nickleback, Creed etc are/were 'selling out'. I'd say they are/were 'staying true' as much as any Arcade Fire are now. I'm sure Linkin' Parks heart and passion are as much in the right place as anyone. They're not the right examples IMO. 'Selling out' - a term I despise - has nothing to do with your genre or size or ambition or whatever. It's not going into stadiums or having your song in a beer ad. To me, it's a conscious decision to change what you are doing for the gain of cash and nothing else. Even then, it's no crime as long as you're honest about it. I don't mean coming out and saying "Oh, no, on this album we're just goin' for the villa in Italy". I mean, undercutting your talent - and this goes beyond music - for simple financial gain, to me, isn't wrong, but it isn't right. You don't want to see a pro athlete sign with a shit team for max cash just because they know there's no expectations there, and they can cruise for a few years, stack on the kilos, earn a truckload and coast into retirement. You want to hope that the passion and goal is still competing and winning, but at the same time you don't hold it against them for making decisions that are best for them financially, as everyone would and should. Same with bands, to me. I don't want to see a band that could be making amazing music, or used to make amazing music, that you suspect are still capable of doing exactly that, undercutting that talent and deliberately sabotaging it to create dumbed down, simplistic stuff that sells more to the masses, but at the same time, if they want to set themselves up financially, go for it.
For me personally, I'd like to be somewhere in the middle. One of those bands - and there are plenty - who do have commercial success and all the luxuries that come with it, but aren't making creative sacrifices to do so. Not so much the hundreds of millions and private jets and homes across the globe, but they're certainly still earning a shitload, enough to live well for life. And I think I'd be pretty reclusive. PLEBA style attention would just drive me up the wall, and frankly, freak me out. Mind you, I'd snag me a supermodel in a heartbeat.