Borrowing/stealing, it's the same, because this way you are not evolving the series, you are not breaking something new to the series, something that we haven't seen yet.
If you ask people who have played Castlevania for the first time, through LoS and give them one from the past, the only thing that they will find the same is the name Castlevania.
If Mario borrow elements from Sonic, it doesn't make it a new game or different from Sonic. It will be just a clone with a different character as the main protagonist. So, when you are talking about something revolutionary, then you are speaking of something that no one has ever yet seen before and when Cox was talking about revolution, he should thing it again, because i haven't seen anything revolutionary. Every aspect of the game, has been seen on other games, GoW/Devil May Cry/Lord of The Rings/Shadow of the colossus, are some..... :

Yes, IGA's games, may have using the Metroid exploration style, but they have improved it in a new way and that's all they have in common with Metroid, because they have their own and unique game play mechanics, that no other game has. They don't borrow/stealing game play mechanics from other games. I don't like the way the magic mechanics have gone at the latest IGA's games, they are almost the same in every game. I prefer the way Alucard was executing magic. The combination of the cross with the buttons, was something cool and i would like to see it in new games.