These guys often have the same mentality in the real world.
If they had met you in the real world instead of on an online dating site, they would have still been intimidated by your higher education.
Unfortunately, there are some guys who just feel very insecure when they come across a woman who may know more than them or who may have a higher status in life thanks to her higher education.
He may not want nor feel compelled to hide his profile on dating sites until he has gotten to the point where the both of you have talked about being exclusive to each other.
Until that conversation happens, he may not want to hide his profile on dating sites and you should not expect him to do so.
If you have reached the point where you feel as though this is a guy that you want to date exclusively, it may be best that you bring up this topic.