The thing with Mr. House though is, unlike the other factions, he actually has the technical know-how to back up his claims. He's the founder of RobCo. Every single robot we see in the game was made by his designs, from the Mr. Handies to the Securitrons. Those RepConn rockets we launch during "Come Fly With Me"? Also made by him, since he bought out RepCon fairly early on into his founding of RobCo. Which also means, if the RepConn tour is anything to go off of, Mr. House is responsible for a lot of space travel technology already. There's a lot of futuristic space gizmos in that tour, all made by him. If he could get us into space in 2077, he can get us into space in 2277. He's shown he pretty much knows how to colonize other planets through his creations at RepConn and RobCo. I trust in him.
NCR and Legion talk a big game, but they don't really show a whole lot to back it up with. NCR says they're the best because they're a stable nation, but as we see from a lot of pro-NCR npcs, the NCR is spreading itself too thin and will soon collapse if it bites off more than it can chew. The Legion will 100% collapse the second Caesar dies. Lanius proves that if you let Caesar die in-game and still side with the Legion. House backs up his game with actual proof that he knows what he's doing.