One thing that bothers me in this thread is the idea some people seem to have that indicates an adversarial approach to admissions.
I think students/parents want to get into the best fit college for them.
Colleges want to admit and enroll the best fit class for them.
Nobody is out to stick it to the other group.
Colleges don’t have a Jan. 30 EA notification date because they want to prevent applicants from applying ED anywhere else. In my opinion, they do EA because they want to be sensitive to having a level playing field for those who can’t do ED because the finances matter. They have a Jan. 30 date because that’s how long it takes them to process applications. To do it faster would require hiring more staff which bumps up tuition cost.
Colleges do ED because it lets them give preference to the students who are most excited about attending their school.
Colleges have to make a choice between offering ED or not.
Students have to make a choice about applying ED somewhere and thus committing to attending that school if admitted.