aikidojournal.com
The following excerpt captured my attention:
Other traditional Japanese arts like Judo and Karate have 7-10X the interest, with an art like BJJ surpassing aikido by over 25x. Merely as an interesting data point, yoga, a non-competitive mind/body/spirit art, generates more interest than all the martial arts and fighting sports combined.
Yoga doesn't seem like a good comparison/it's fairly obvious to me that yoga would win out in popularity over aikido, for a number of reasons.
1. Yoga often doesn't cost anything. It looks like he compared them via instagram hashtags - plenty of the people posting on instagram started yoga from a friend/local group or online videos, which are very abundant and free (and with no stigma against them). Compare that to the one Aikido place I checked out which charged 125/month for twice a week.
1a. If you're going by instagram, the data is skewed. Most students aren't posting videos/pics on instagram of training in a dojo, that's done by the instructors normally. So if people are practicing by themselves, they can be posting the videos/pics, which increases it's insta presence.
2. Yoga can be done by yourself if you want to, which lowers the barrier for unfit people, as there's no way for them to be embarrassed about it.
3. In martial arts you're actively learning skills, which requires more mental effort (in my experience) then following along with the stretches/poses of a guide. So even if physically the strain might be the same, that mental toll can add up.
4. Going along with the second and third points, there's no time table for it. I can do yoga once a month, and not 'unlearn' any skills (though my flexibility will regress), I can't do that for BJJ. And if I disappear for a couple weeks when I'm not feeling it, I may feel uncomfortable going back, knowing everyone's going to ask where I am. Normally this peer pressure is seen as a good thing (keeps you there) but it also frequently works in the opposite way.
5. Yoga doesn't claim to be a martial art. If you compare it to Aikido, the mental image is that it's a martial art, so people looking for martial arts will look at Aikido, read online about how it sucks, or discover it's not meant for fighting, or whatever, and choose another one. Meanwhile if someone's looking for a mind/body/spirit exercise, they're not going to look at Aikido at all, because it's considered a martial art, and they're not looking for one. Essentially Aikido is trying two markets and being the lesser option (in the public's mind) then other things in both markets.
6. Again, yoga doesn't claim to be a martial art. And a lot of people don't want to do martial arts. They have no interest in fighting people. So obviously, something where you don't have to fight people will be more popular than something where you do. I wouldn't be surprised if things like cycling, board games, tennis or soccer all surpassed individual martial arts in insta popularity as well.