I'm thinking Aikido may be similar to Kung being that in practice people rarely do the form from the perspective of fighting. Movements are usually much slower than what is needed for fighting and the movement is often cleaner. The intent to do harm and the warrior mentality is often missing. People can be good at it, but that special focus of aggression if often gone.
Here's one example. Same type of techniques I train but when I train and do my forms I'm actually visualizing me fighting and moving as I would if I was fighting. But as you can see in this video. This person is not thinking about beating the crap out of someone while doing the form.
Same issue here. Looks good, but it's not fighting movements. You can look at it and it doesn't have that feel that she's fighting.
Now take a look at this. Simple punches, but the focus is different. He looks like he's fighting an imaginary person.
Now aikido. This is not fighting movement. The urgency is not there. I can guarantee if an attacker lit off his attack like the shadow boxer then that Aikido slow movement is going to lose. If you don't train to deal with fast strikes coming in then you'll never develop the timing and adjustment required to do any of the techniques one may learn. And it's not just the hand speed, but the foot speed also has to be there. If the practitioner is never training those things then it's not happening. It doesn't mean the art isn't for fighting. It just means the person isn't training it as they should.