That's because the new Aikido is not the same as it was 50 years ago. It constantly develops and gets more aggressive. My son has a brown belt in Aikido (also he has learned Kudo and Sambo). I've seen how his coach has learned the kids. Like "when somebody attacks you, punch him in the neck, drop him to the ground and stomp his head with your leg". That's because everything is evolving and changing. Aikido today it a much different thing as when it was invented. If you want to succeed you have to practice your kicking and punching technique and course you have to spend hours in the in the gym lifting steel. Nowadays it doesn't matter which exactly martial art you learn. The only thing that matters is
how you do it.
A Korean guy who has learned Russian martial art
Systema which has a lot of common with Aikido (you know Russians are obsessed with math and physics, and that's that he shows: a real life physics of human's body):
In fact, the Russian Systema technique is nothing but just the elementary physics that you have learned in the school.
Some say it doesn't work in the real life, but I have serious doubts about their assumptions...