It was not made entirely by Hideki Kamiya. And Capcom owns the game. There is no "Hideki is victim". You should stop thinking that way. It's not justice.
Capcom paid Hideki and others to create a game - and they did. Of course Hideki are saddened by DMC not being lead on by him and his team, but bottomline: the game is Capcoms. Everything that Hideki and other made that DMC consists of is Capcoms.
You know what i have observed by DmC controversy? People saying "Great job Ninja theory" despite Capcom helping Ninja theory alot with gameplay. And i have also read that Capcom is doing the bosses (?).
And on top of all of this Capcom is paying them.
And despite Capcom's role in DmC many people seem to forget that and give all credit to Ninja theory. They go as far as calling DmC "Ninja theory's DmC".
Let's face the facts: the gameplay is Capcom's concept. The character concept is Capcoms. The world of demons is Capcom's concept etc etc
Sure Ninja theory has a big role in DmC but as i pointed out many of the concepts they are using is already there for them to work on. Such as gameplay, character, items etc
And since Capcom is paying Ninja theory for their work - how is it then Ninja theory's game?
Just like Hideki were paid to do a job, Ninja theory is being paid as well. DMC and DmC is Capcoms. And i don't think there is any good argument for why Hideki should have right to make the next DMC or rights over the game itself.
Imagine this scenario:
"Capcom: We paid you to make the game for us, you accepted the money. And now your regreting your choice and want to steal the game from us?".