We are going to get to the stage...or perhaps are already at a stage, where anyone can open a club and call themselves a 10th dan or shihan or soke or grandmaster or founder or professor.
Maybe one style will focus on weapons or immobilisations or projections or kata or randori or ki or health or ukemi.
I come from Judo. Judo is described as 'that which was created by Jigoro Kano'.
Surely Aikido can be learnt from what was created by M Ueshiba?