As far as I know, it is just a matter of
language;Aikidoka is the Japanese way of calling an Aikido performer.
In Spain we say Karateka, Judoka...so
why not say Aikidoka?
Of course my Knowledge of English language it's not so deep to know how should it be for English-speakers.
Anyway, is it SO important to lose time in discussions? Or is just better to focus in the practise whatever are we called?