And yet...there are no scientific comparisons, studies or data with a clearly demonstrated advantage for training in Yoshinkan - why doesn't that cause a problem for you?
For that matter, the UFC generally derides most traditional arts, including Aikido (even Yoshinkan Aikido) - so how come you don't follow the "credible opinion" that you yourself are citing?
Thanks for asking- it's because I'm old now. When I was young we had to mix our own martial arts, because there was no UFC to point the way back then. So I have belts in Yoshukai Karate, Goju Ryu Karate, Shao Lama Kung Fu and Judo, plus my Aikido rank. In my late 30's, I liked to train at our local MMA gym, the Academy of Mixed Martial Arts, but now that I'm in my 40's I know I don't have another 20 years of that left in me. Honestly, I don't even want to train as hard as the 20-something UFC wannabes, let alone compete with them.
I want advantages now, and I don't want to work as much to get them. Yoshinkan Aikido is gentle enough that I can train hard into my 60's but still adds legitimate skills to my repertoire. And it works. I know that because I took it to the Bullshido Throwdown in Skokie a few years ago and made it to the third round of competition without using anything else. Two submission victories using wristlocks off my back, by the way. That's data, and it was scientific enough for me.