You're right, they really could have, but they didn't for whatever reasons. We may never really know why things went the way they did. But man did the final product just scream low effort mess.
Then the whole use of community created mods with out any recognition, saying it was an accident that was only in footage, but then having it all in the code. So, they lied about it. The whole thing really has been handled so poorly. It's like the GTA Remastered Collection again, if not worse.