HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

I think it's more of a habit thing. For people who don't play with SoD+HD, such a change would actually be inconvenient.

Yeah, I agree, it's a matter of habit. But for some reason, HD-style doesn't work in WOTG. I don't know if it's a flaw in HD, or if it's impossible to implement it in WOTG.