You cannot seriously compare a rendering/posing/animation tool like Daz with a character manager for a game.
1) You can adapt Daz to whatever kind of artwork and graphics you want. That means the characters won't look Asian no matter what you do. It is so fucking funny to play a game with HS screenshots of a girl named Kenzie when it is so obvious that she's Japanese.
2) You can easily add 3D objects from any 3D tool and make new ones yourself.
3) Daz renders scenes with raytracing and post processing. Because it takes time, you cannot seriously compare a real-time screengrab/scenerecording tool with a full blown renderer. If you do, you just explain that you know nothing.
4. Daz has been used to make animations for movies and TV shows. Please tell me that anybody used Illusion captures for that. Please???
Your argument falls to the floor simply because you can do whatever you want in Daz. It takes longer, and most importantly, it requires a little skill. Those without those skills probably choose Illusion games for their artwork. But the question is, should they even make games then?
(Granted, there are okay games made with Honey Select)