Short Answer - Universities

Long Answer:

To get and hold a job as an academic, you must continually produce "high quality research". To get the job, in the first place, you must also be seen to do this.

"High quality" is often metriced by universities to mean "published in high impact journals" and "well cited". This metric is known to be faulty, but universities really dislike change.

So, to get a job, you have to give up your rights to your research, and to keep your job, you have to do likewise.

Worse, in the current financial climate, academia is seeing unprecedented cuts, which further entrenches this issue.