Because instead of filling the game with repeated characters. Not include: Sabretooth; Cable; Omega Red; Silver Samurai; Electro; Sunspot; Bishop; Black Heart; Kraven; Taskmaster;
Welcome to the forum 
There’s a separate forum for Suggestions and Feedback. This forum is really for discussing characters that already exist in the game.
Actually there is a Speculation and Concepts subforum (505 Go! Official Forums) of the Character Discussion where this should end. Suggestions and Feedback is more connected to the overall gameplay concepts, UI concepts and feedback on the play-ability of the game.
I think it’s a great example of how badly the forum is partitioned in light of the frenzy of moving posts around.
The only reason the Speculation & Concepts subforum even exists is because we used to have an ongoing Spoiler thread. A few players checked the coding and would give us hints on upcoming characters. In order to hide this thread, an entire subforum was created until it was ultimately shut down for good nearly 2yrs ago
What is the address of this forum?
Sure hasn’t stopped spoilers from coming out. But anyways, kinda makes sense for character ideas to fall under “suggestions”, it’d help de-clutter the forums a little, I think.