I agree in the fact that many people do not engage in "dynamic" aikido practice -- meaning that it seems many are content to repeat techniques in a, say, 4th kyu fashion for 20 years.
My teacher often tells his students during his regular classes to not do the same exact technique twice but to do, say, four different variations on the same theme. Sure, they may all be katatedori shihonage, but make them different. As such, I'll very often give slightly different attacks as uke in respect to timing, intent, and so on. This is still within the context of "kata" training in my mind and, to my understanding, happens in the context of such in koryu arts as well.
Relatedly, it often amuses me to see people in aikido tests being able to successfully do the technique that's been called every single time -- even if the technique were not appropriate for that attack. I hardly see people just avoiding the attack if that's all they could do.
I also agree that the "aikido is too dangerous to be used against people who are resisting" argument is flawed as other martial arts like judo and jujutsu work against people who are actively resisting. The auxiliary argument of, "but martial art XYZ is a 'sports' martial art and has rules" doesn't really do too well in my eyes as aikido practice has many, many rules as well...
As Ushiro sensei at the Aiki Expo said, his wish was that if people in aikido learned more "effective" ways of attacking as uke that the whole art would benefit. I can't agree more...