“The aiki-arts (aikido, aikijujutsu, hapkido, et al) are ineffective for fighting and incapable of teaching practitioners how to defend themselves against even the most inexperienced attacker, let alone a seasoned martial artist.”

As a practitioner of both aikido (one aspect of Taikyoku Budo) and Brazilian jiu-jitsu (BJJ), I have spent a lot of time contemplating this argument, trying to find my footing and discover my own truth and my own path. When in doubt, I feel it wise to refer back to the beginning and, for me, that means Takeda Sokaku.
Takeda Sokaku was the founder of Daito-ryu aikijujutsu, the parent art of aikido and (traditional) hapkido. Takeda grew up, like most kids of his era, sumo wrestling for fun. In his youth, he competed in many local sumo tournaments, against much larger, stronger wrestlers, and he often won. As he began studying more traditional grappling and weapon-based arts, Takeda traveled around Japan, visiting various dojo and taking part in challenge matches to test his skills. Even after he developed and began teaching Daito-ryu aikijujutsu, he continued to practice sumo, informally sparring with his students before or after teaching.
Daito-ryu aikijujutsu itself did not formally incorporate sparring, however. Obviously, Takeda was not opposed to either randori (friendly inner-dojo sparring) or shiai (inter-dojo competitive bouts). He did both (maybe we should also). Why then is there no randori or shiai in Daito-ryu aikijujutsu or other aiki-arts in the way we see it in BJJ for example? Perhaps it was not meant for that. Maybe it was intended to teach its practitioners something different, something that would translate to grappling, striking, or weapons and would make the practitioner more effective in randori or shiai within these contexts, but which is not itself intended to be for ‘fighting.’ That would also explain why the aiki-arts, in their outer form, do not appear to lend themselves well to sparring or competition. They are not supposed to and that is okay.
“As in life, so too in budo. As in budo, so too in life.”
-Robert Van Valkenburgh is co-founder of Taikyoku Mind & Body and Kogen Dojo where he teaches Taikyoku Budo and Brazilian Jiu-Jitsu