There's nothing stopping a kickstartered game getting further external publisher investment.
Wally would be the one more dead on. If you can get your game primarily funded by Kickstarter folks, and be beholden to no one (backers ain't making Schafer n co sign contracts for this, unlike what a publisher would), then of course that's a route to go.
Of course they'd likely never be able to make a Brutal Legend 2 or anything on par through Kickstarter. And given Double Fines reputation with publishers (hence part of reason going through KS) I've a feeling they might never see that kind of project again. Though I guess Schafer might be using Kickstarter to force him and his team to learn to stay in budget, thus making them more appealing to publishers again for larger projects that'd make use of whole team. I dunno, long term on this is hard to see. DF jump all over the place in terms of scope of games, and KS is still very early stages to be a solid continuation of funding, compared to the decades old publishers.