Sure, Valve or similar could just give them all the money (and maybe they are giving a significant portion), but that wouldn't involve the community- pulling in indie gamers and fans alike. Just like relationships with (good) investors- the money isn't the only asset.
Will this be perfect? I highly doubt it, but its an incremental step in moving us forward in a field that's remained stagnant on the consumer front for nearly 20 years. We need lots of beautiful failures to get to perfection.
"Involve the community" is a vacuous statement. It doesn't mean anything. What involves a developer community is company support, some indication that the work they do will exist and be profitable. If Gabe Newell really liked it, they'd all be wheeling around desks at Valve by now, and Source engine games would all support this in a couple of months. And then you would see other developers eat this up.
You don't need to "involve the community". You need to show them a reality.
Note however that there's nothing to indicate this isn't happening in parallel. Valve may have a good sized team working on making the Source engine work very well with this now, and for all we know contributed $250K that's not included in the Kickstarter.
Will this be perfect? I highly doubt it, but its an incremental step in moving us forward in a field that's remained stagnant on the consumer front for nearly 20 years. We need lots of beautiful failures to get to perfection.