In the current "next gen" environment it kinda seems like being a mediocre game is a far worse crime than being a bad game. Granted I don't personally have any drive to try Knack. I just really doubt it deserves it's meme status for being an (apparently) meh platformer.
But it isn't a platformer it's an action game, I think it would be better if people saw it like an evolution of the Lego games (but instead of open it's linear). It also is a game made for a younger audience so I can see why so many adults are complaining about how it's not next gen enough for them.
As I understands it a lot of kids today start with the Lego games and if you see it from that perspective it's easy to see how Knack could be a great transition for those kids into more complex games. The Lego games is more or less mash a button to defeat the enemies and knack have a similar (simple) control scheme but with one important difference, placement. This is the reason to why I have enjoyed the game as much as I have. The whole game is about pattern recognition and placement.
With the most popular games for the "core gamers" now being DS/Bloodborne and monster hunter I can see how kids that have played knack will have some basic understanding to how these games are played.
The variations and reskinned enemies is also a good thing if you want the kids to learn the tells, feel like they are getting better and continue to play.
I also find that the different size of knack is a great distraction to make the combat feel less repetitive and the fact that you almost always have a human ai that follows you let you constantly confirm how big you are at the moment.
I think that the problem with Knack is that a lot of people thought/think that it is a platformer, which it isn't