You seem very certain there. You aren’t completely wrong but…

So you are right that Jordan didn’t plan for Sanderson to finish his work. He did however plan for someone to finish. He dedicated a lot of his remaining time to getting it fleshed out with written and audio notes so that someone could finish his work.

It was his wife (and editor) who chose Sanderson following Jordan’s passing.

The second point is certainly wrong (when applied to the wider fanbase) and I am unsure why you are so certain about it.

There have of course been complaints about Sanderson’s novels. His writing style differs and some of his characters feel different to their appearances in the previous works. However, even with those complaints people have been appreciative of the books overall and grateful to get an ending. The overall reaction has definitely been favourable despite any complaints.

Possibly you just find yourself within a small echo chamber of miserable fans?