The issue is that the authors of bad papers still participate in the peer-review process. If they are the only expert reviewers and you do not pay proper respect to their work, they will squash your submission. To avoid this, papers can propagate mistakes for a long time.
Personally, I'm always very careful to cite and praise work by "competing" researchers even when that work has well-known errors, because I know that those researchers will review my paper and if there aren't other experts on the review committee the paper won't make it. I wish I didn't have to, but my supervisor wants to get tenured and I want to finish grad school, and for that we need to publish papers.
Lots of science is completely inaccessible for non-experts as a result of this sort of politics. There is no guarantee that the work you hear praised/cited in papers is actually any good; it may have been inserted just to appease someone.
I thought that this was something specific to my field, but apparently not. Leaves me very jaded about the scientific community.