So these are stats from competitive sports situations where two evenly-matched opponents agree to fight by a certain set of rules. I think it is important to not train with that mindset (unless you are a sport fighter). Aikido doesn't fit very well there, in general, and you aren't going to have an evenly-matched opponent mug you according to a set of rules. When under duress, you revert to behaviors you have burned in. That's why I think it is good to have a core practice where you receive a single strong attack and practice dealing with it as though you will die if you don't get it right.
Those stats are the most readily available, which is why I quoted them. Don't get stuck on the boxing thing, I said before and I'll say it again - I'm not advocating boxing.
I don't think that the percentage of people actually connecting with strikes in a non-sports situation are any higher, and they're probably much lower, which only strengthens the argument, IMO.
People used to train intensively in Kata to refine certain skills - then they'd go out and fight for their experience. Most people don't do that anymore, which means that the training paradigm needs to be looked at more closely.
It's not a new problem - Musashi complained about it too.