What’s really wrong with Sandersons prose?

I'm an inspiring writer who's currently working on my first book. I was wondering if I could get your guys opinions on Sanderson's prose which seems to be an unending topic of discussion on this thread (Sorry for adding to it).

The reason why I ask is im of course trying to get my prose to the level that would help it get published. Sanderson's prose is often considered simple and many of the sub wont even read his books because of this. (Yes I know its 100% at the level to be published)

Personally I find this a little odd. I've never really taken huge notice to prose while reading. If I hadn't spent so much time on this sub I would have never even known how many people find his writing to be weak in that regard. I'm pretty much a 100% story guy and as long as prose is fine I wont care about it.

So im trying to figure out what you guys don't like about it? Like really getting down to the details of what you feel his writing is missing so I can perhaps consider that while working on my own book. Think like emotions, metaphors or just words he chooses to use) Forgive me if you find it obvious why his prose is considered simple I’ve never been the brightest bulb in the pack.

I just don't want my book to have completely simple prose. Obviously it would still be an achievement to get my prose to Sanderson's level but I also wouldn't want people to be turned off by my own prose. (Don’t take this post the wrong way I like Sanderson a lot!)