does it seem to be legitimate ignorance or maybe folks pushing ahead regardless of x being disproved?

IMHO, It's mostly ignorance coming a push/drive to "publish or perish." When the stakes are so high and output is so valued, and when reproducability isn't required, it disincentivizes thorough work. The system is set up in a way that is making it fail.

There is also the reality that "one paper" or "one study" can be found contradicted almost anything, so if you just went with "some other paper/study debunks my premise" then you'd end up producing nothing. Plus many inside know that there's a lot of slop out there that gets published, so they can (sometimes reasonably IMHO) dismiss that "one paper" even when they do know about it.

It's (mostly) not fraud or malicious intent or ignorance, it's (mostly) humans existing in the system in which they must live.

Poor scholarship.

However, given the feedback by other reviewers, I was the only one who knew that X doesn’t work. I am not sure how these people mark themselves as “experts” in the field if they are not following the literature themselves.