According to Ayoub, “From a technical standpoint, you look at the architecture of the Xbox One and there are some similarities to the architecture of a modern PC. That certainly makes that sort of cross-platform development easier.” However it seems that while technically it makes sense to port the game over, the size of the Halo games makes it a lot harder.
Ayoub cites the Master Chief Collection as an example. “Master Chief Collection is massive. We have to coordinate four games, 100-plus maps, a lot of new cinematics, and Halo 2 Anniversary.” That and the fact that making the PC version would also distract them from creating a great console game.
This isn’t what PC gamers probably want to hear right now, but hopefully this clears up some of the reasons as to why there just aren’t as many Halo games on the PC compared to the console. Perhaps down the road we could see more Halo games brought onto the PC, but in the meantime we guess if you want a Halo experience, you’ll probably want to get a console.