When I was a young kid in the 80's I thought Steven Seagal was a real badass, and Aikido was THE best (and coolest) martial art. Watching his movies and fight scenes was like watching that video at this website. Effortlessly using attackers own momentum against them, snapping limbs and the principle of no fist/kick hits harder than the ground. I remember going to the library and getting some Aikido books and practicing the steps from photographs.

Then Royce Gracie with Brazilian Jujitsu and the very beginnings of UFC came along and completely upended the traditional glamor of movie star Martial Arts for REAL fights against opponents of all sizes (Early UFC didn't have weight classes). Most real fights end up on the ground pretty fast anyway and against larger/stronger opponents you want to be on the ground.

That isn't to say that a black belt in say Karate, or even Aikido wouldn't still be effective in a no-choice self-defense situation, but I'd rather be more proficient in Boxing at that point or one of the many other more modern fighting arts that have grappling as a core.