You really have no idea how governments solicit corporations to their areas, do you?
Nowadays, corporations look for the most favorable places to operate. That could be a place that's desirable to live in, a place with a large population that's qualified to do the work, a place with favorable laws that make land-use or permitting easier, or a place with favorable tax laws that make it inexpensive.
New Mexico has some really beautiful places like Ruidoso, but it also has a lot of land that can't even be used for ranching, and short of mineral extraction there's no interest in economic development there. There's a reason why the Manhattan Project tested the first nuclear bomb there; it directly impacted only one family whose land and ranch house were taken from them during the project and couldn't be returned afterward due to the contamination.
On the flip side, Virgin Galactic needs someplace to play with their vehicles. There's a certain, higher than average risk associated with these vehicles. There's also the possibility that future vehicles might not be mothership-dropped and instead might launch from the ground, which would further increase the risk associated with them. This means that they need land, land far enough away from others that the risk to the population is low, land as a buffer in case of accidents. This is the same problem that modern air force and navy air bases face; they're built a distance from a supporting city to try to minimize the impact on the city, but the city grows to the base's edge then gets upset that the base is there. So the solution is to look for someplace to build the facility where it won't impact anyone.
Now, the downside, it's hard to attract talented people whose ability will let them write their own check to places that aren't terribly desirable to live. New Mexico has harsh climate, its cities aren't exactly known for being centers of modern popular culture, it lacks world-renowned education, and it doesn't even have major sports teams. That means staff need even more compensation to come there.
If New Mexico wants both the immediate business and wants the longer-term infrastructure that could make it a hub, that means they have to find a way to attract it. The only major means at their disposal are tax relief and easy permitting. That costs them and doesn't guarantee that it'll work, but the payoffs for the risks are generally pretty favorable.