We see in Chinese arts how internal power is used, and then we see how O'Sensei, and others use their internal power that has different results.
There is not perfect art, each art has its strengths and weakness, especially on how it is apply, and not everyone applies it the same or looks at it the same, or uses it the same. There is no art that has only strengths and no weaknesses. Some arts use the same principles packaged differently to shove people across a room, to fight from the ground, to throw, and others who focus on countering, some defensive only, other offensive, some use both. It is like using the same limited ingredients to get a variety of the same dish, with different chefs adding their style to the dish. I am thinking pizza for example. That is what I am saying about internal power.
Some people apply principles better then others, and for every person good at it, there is someone out there better. Not everyone is equal. You have your talented and those who don't get very far. There are a few who make it to the top in skill and understanding, like any field does. Not everyone is or can be a "star."
This is how I look at it. I don't see why there has to be harsh criticism made toward Aikido. Maybe because it is the benchmark, it is the gold standard? Maybe it is the guy everyone wants to beat. Isn't that who you'd want to study from, the gun slinger everyone is gunning for. Who wants to study from the challengers? You want to study from the guy everyone is gunning for.
Aikido offers other things beside just physical skill, there are other dimensions to Aikido. We live in a society, a world, where old combat ways have given way to modern combat, and weapons, and law, and police, and all those things that make martial arts, arts. Because of that there are arts, and people seek them out for a variety of reasons and not all for combatative reasons. If society and the world was different just as in the past, the sole reason to learn to fight and develop "internal power" is because that was the most powerful thing. There was nothing else than, no modern weapons, no laws and all that. So the top of the heap was what we know now is martial arts.
So may be a better measurement of martial arts would be their complexity, intricacies, and that kind of stuff. Because martial arts, most of which are like Aikido and have other sides and philosophies to them. It's ok to measure them on a single angle, but that only gives us a small slice of what an art is and can do or be.