First of all, they were wasteland tested. As impressive as the Securitrons were, House still needed his human forces to act as something of an ad-hoc army in the beginning while he was solidifying his grip on the area, as seen in the banishment of the Khans and the first meeting with NCR at Hoover Dam. A vault full of people who hadn't had to deal with deprivation, post-nuke living conditions, or non-diplomatic conflict resolution for over 200 years didn't fit the bill.
True. Good point. But it didn't need to be an either-or decision. He could have recruited both.
Taking off from that last point, the 21-dwellers were already a cohesive unit with a strong sense of community and a rigid, highly specialized way of life. It would have been far harder to break and condition that. With the tribals, he was offering them a ticket out of conflict and wasteland subsistence, albeit at a high cultural price. With the vault dwellers, he would have been entirely destroying not just their culture but their world entire, evicting them into a wide-open wateland that was completely alien to them and forcing them to play pretend in ways that their knowledge of the pre-war world would cause them to view as utterly demeaning. Unlike with the tribals, he wouldn't be offering them much for what he was taking, and the dwellers having grown up literally surrounded on all sides by pre-war technology would make it harder for him to play the "Wizard of Oz" angle for shock and awe. There'd have been no leverage over them but the threat of violence.
He wouldn't be depriving them of their culture. They were gamblers, presumably descended from the very people who used to populate the Strip in pre-war times.
My point is, he didn't need to evict them. He could have let them continue to live in the vault even while they worked in the casinos. If they were agreeable (and the Vault 21-ers you meet seem open minded enough), he could have made Vault 21 itself into a casino, populated the other three with tribals, and had four casinos open to the public.
If House had peopled the strip with the V21 inhabitants, he would have had a pissed-off and alienated group of misfit fish-out-of-water who all still shared a sense of common identity, held a grudge, and knew their way around a vault-tec circuitboard. That's just asking for trouble. Instead, he pulled a reverse-Caesar, letting the tribes under him keep a measure of autonomy so as to keep his forces in manageable, power-balanced parcels. He then took the one large, well-organized, tech-savvy group that could possibly comprise an internal threat to his vision of Vegas and scattered them.
If he thinks they'd be a threat, the last thing he should be doing is going out of his way to piss them off. If they wanted to interact with the outside world, he could help them set up a casino where they do what they do best. If not, he didn't need to worry about them.
I'm sure he retained some of them, too-- he's not stupid, and if he's going to keep Sheldon Weintraub around for something as trivial to the infrastructure as neon signage, he has to have kept others. I'd be willing to wager that some of Vault 21's best technicians were instrumental to the early establishment of the strip and the surrounding communities-- it's just that Fallout's populations have never been to scale and we didn't get to meet these people explicitly. For all we know, half of Freeside could have been from Vault 21.
Good point. But at least Doc Mitchell left the area. Which means that the NCR high-rollers have to get medical treatment from the Followers with all the poor people.
They're there for the strip to make use of their expertise when needed, but House has no responsibility to them and he can keep a healthy distance between them and his operations, which suits his free-market outlook just fine.
His free market outlook is exactly why I question this decision. Having the state seize private property with no compensation isn't very free. Granted, he never explicitly expresses a devotion to capitalism and property rights, but he does say something like he isn't interested in how people live their lives. Destroying an entire culture simply because they
might be a threat is more like something Caesar would do. At least with the Brotherhood of Steel he had a good reason to believe they were a threat, based on their ethos and past behavior.
So, maybe I misunderstand his political philosophy, but the main criticism of Mr House seems to be that he ignores people and their problems, which doesn't seem like something a statist would do. But I guess in one of the ending slides he does invade Freeside, which supports this perspective. So what is his philosophy? "Government doesn't exist to solve problems, it exists to seize property."?
You do make a lot of good points, though.
EDIT: I keep forgetting that House didn't seize the vault, he won it. Which in turn shows that there's no reason he couldn't have tried to win whatever cooperation he wanted from the residents. Also, re-reading the ending slides makes the situation with the Kings somewhat ambiguous.