I think that's sensible, but it's risky to assume that the best way of achieving that is doing things the way they have always been done. Kickstarter games are inherently different. You have a huge built in audience that are more invested in the game, but paid you for it years ago so don't bring in any actual cash on launch day. The value of existing marketing is known to agree (except the 75k people most likely to be interested in your game won't be, because they already backed it) but there are other questions to consider. What would the value of giving backers access the same time as the reviewers, but ahead of the general public be? There's a lot of things that factor into that choice - the big ones being how reliant you are on that day-one patch for stability (especially if you're Obsidian), the other being if you plan on going back to Kickstarter for the follow-up next game, and if so, when.
Other than the game itself, that launch is the last window to talk to most casual backers. I think it would be wrong to underestimate the effect on them of saying "as a reward for supporting us, you'll get access to the game a week before the general public". Is that expected? No. Are backers entitled to it? No. But is there value in doing that? Yes. Early review copies are handed around like free candy in the games business, especially smaller companies after any sort of coverage, but to the casual fan, getting that early copy can be super-cool. Even if they don't play it, it makes them feel special, it has a big positive effect on backer engagement. You're far more likely to get that backer back again for the next project. And there's the negative flip-side too. Backers that have forgotten about the project see all the videos and so on, get excited, but don't get a call to action. They don't need to pre-order, but they can't play it either. Currently there's not even a pre-load/key available. That inability to take any action can lead to the game being forgotten about again.
Now, for all those pro points of releasing to backers early, there are absolutely drawbacks too. Does one outweigh the other? I don't know. My issue is that the impression I get from various responses is that no one really thought about it. They just did it this way because it's the way it's always been done. And that's where it can get dangerously short-sighted - to assume that your Kickstarter game, once you have the money, works exactly the same as any other game. There are differences, a lot of them aren't even fully understood yet, but they need thinking about, not ignoring.
[As an aside, this is a more complicated case - PoE has publisher funding now too, and it's huge, and there are issues with spoilers... but the first time I encountered this sort of thing was backing an album from a musician. That was a lot more straight-forward: the backers literally paid for the studio time and production, and then the album was sent out to reviewers first. Backers had to wait a couple of weeks. ]