I mean, I can understand where CBR is going with that:
The issue with SSJ3 is how completely out of nowhere it comes up and feels like it's only there to get Goku and later Gotenks out of a bad spot.
The problem with what CBR is doing is less that SSJ3 is bad writing but that there's nothing leading to SSJ3 even being a thing, even moreso than SSJ2 was.