The big thing here is that the idea is a "mascot beat em up" from a first party company's respective IPs or historically associated IPs
In that sense, it is pretty blatant where the inspiration came from (Smash Bros) and to suggest otherwise is fully and wholly disingenuous on any person's part. Its ridiculous seeing some of the round-about defensiveness that is coming from it...it was clearly inspired by Smash Bros' precedent. In that sense, Kamiya is correct.
That said, from what I understand, the game plays & feels differently from Smash Bros in the sense it is not a "cut and paste" job but truly a different take on it, the mechanics, and "feeling"... similar to how Street Fighter and Tekken are both 1 on 1 fighters but have different mechanics, or even Tekken and Dead or Alive.
There is nothing wrong with that, and nothing wrong with a Sony studio making a game like this. It might not have the star power of Mario behind it, but some gamers (such as myself) will always be interested in selecting Kratos and beating up Parapa the Rappa in a more arcade style fighting game.
The issue on one side is that (some of the) more Sony rooted fans are refusing to acknowledge where the obvious inspiration originated from (Smash Bros) and the issue on the other side is (some of the) more Nintendo rooted fans cannot seem to understand the game might play entirely differently the way Dead or Alive and Tekken are different. More fighters like this is never a bad idea. This is the video game industry, and ideas are "taken" all the time. Or are we going to start blasting Nintendo for copying Sony's "clicky" sticks?
I plan on getting this for Vita