I have different control schemes for every Halo, and though it was funny how grenades switched button on me literally every single Halo game (Boxer pains), it never took me long to adapt to it, because I just saw it as a different game.

Forge is the same way. I look at it as a map editor, rather than as the monitor that we floated about and spawned things with. It took me all of ten minutes to completely adapt to the new controls, and in order to test it out, I decided to remake a Black Ops 3 map that I had just played on minutes before. It took me all of five hours to learn he controls and make this:

I only made a few maps in Reach, because it took me 25+ hours of work to get my Loading Bay map to a level where I was happy with it, given all of the limitations and sacrifices that I had to make, while constantly having to correct mistakes and nudging each piece one by one a lot.

The new controls are highly intuitive and vastly superior to previous Forge tools, and are one of the highlights of Halo 5 for me. And remember that they were made with the help of real Forgers, not chumps like you and I. They were clearly happier with them this way. I really don't see what the issue is with them, although I wouldn't be against them adding control schemes for convenience.