I've trained in Aikikai as well as most of the other main organisations - currently I am not Aikikai and have no intention to return.
My observation here is about my region/area .... "... don't like Aikikai" is probably too strong/emotional.
What's coming across to me is that the local Aikikai does not interact with other aikido groups. End of story.
My impression is that they do not like their students to interact with students in other clubs or organisations, or attend other clubs' seminars ... which to me is contrary to the spirit of aiki. I don't know if this is an/the issue in other countries.
My observation is NOT about clubs that have their roots in Aikikai but the main Aikikai organisation locally.
You'll love this then - one Aikikai organization run by a Japanese shihan not recognizing a dan rank issued by another (the certificate came from hombu, just like all of them) and requiring a student to re-test.