Is there anyone stopping them from going into that study or does it contradict their world view
To be fair, 90% of the lack of conservatives in sociology is that they don't give a shyt about that field but there really is discrimination against them that has some impact at least.
If you're openly conservative and trying to advance in sociology then you'll probably be mocked by your professors, you'll probably run into difficulties getting your thesis approved, you'll probably run into difficulties getting hired, you'll probably run into discrimination trying to collaborate with colleagues, etc. All of that makes it less likely that they'll enter the field.
There was a survey back in 2012 where a significant % of social psychologists admitted that they would be biased against a conservative colleague.
Survey finds that social psychologists admit to anti-conservative bias