There are many who are a little too enthusiastic about the BS books, but most of them (by far) have long been solid bashers of Jordan.

It's understandable, those readers have long stopped being "fans" of WOT as such, and are rather fans of some specific aspects of the series and bashers of many other aspects. They stick to it because they'd hate not reaching the end of the story after so many years.

OTOH, it's harder to believe they genuinely find those books superior on the whole to any written by Jordan. Even those who are big fans of Sanderson can hardly see a deep Sanderson's touch in the WOT books, and few who aren't all that happy with Sanderson's work on WOT hardly if ever complain that it's because there's a "Sanderson touch" in the work. The writing style is not his natural one, the book structure is hardly similar to anything he's done, and the pacing, or the way he approaches certain scenes is not his own either. It's not that, it's very specific and limited problems with the books, problems Sanderson's works don't really have, due either to the limitations of what a second writer could hope to achieve, and even more due to the circumstances in which the books are being written. And I can really see how anyone would call the WOT books Sanderson's "best work" either. They feel rushed and there's a lot of ackward stuff in them. A lot of the "best stuff" in them is also most likely due to Jordan himself. Sanderson himself most of what happens in the books, all the conclusions, all the important turning points for everyone, is mostly straight from Jordan's notes and he had not many to create from scratch and was more concerned with the details of how to reach those points from the end points of KOD (especially for more minor story points, where Jordan left notes on how he planned to conclude it, or options to do so, without elaborating on how exactly this was to reach that point... it's often there, IMO, that Sanderson was a bit disappointing. It's obvious for instance Jordan gave him the whole explanation for the "too young sitters" mystery, or how the BA hunters would end up under Egwene's thumb. What's disappointing is the "build up" to those events, which felt too simple compared to the way Jordan used to write those scenes. It's in stuff like this you really could see this wasn't Jordan at the helm anymore)

It especially feels very weird when some people credit Sanderson for the fact all of a sudden a lot of stuff is happening, for instance. I don't know what those people think RJ was doing when he spent books like COT putting stuff into place for later, if not precisely making sure everything was in sync so he could have exactly the fast pace finale he had in mind, and without altering his plans for the important characters by "cutting to the chase" just to get to the final book faster. Some of those required more time than he thought, so he did slow down some storylines that were too advanced rather than change their outcome. .