Why can these things happen?

Imagine:

Funding and research and publications and citations and teaching and further research.

For example:

Funding favors Topic A

then

More scholars research A.

then

More articles about A are published.

then

More scholars cite those articles.

then

A becomes prominent in the literature.

then

Universities teach A.

then

Students become interested in A.

then

More scholars research A.

That can create a feedback loop.

But remember: this demonstrates a possible mechanism, not automatically proof that Topic A is wrong or ideologically imposed.