I have much respect for your point of view, and I too would like to believe that there is a "middle way." I also see wisdom in the observation that people who don't train against seriously committed attacks may be ill-prepared to defend them. Speaking on behalf of fellow (pre-dan) klutzes, however, I sometimes feel in aikido technique classes that I'm treading water simply in trying to follow all the mechanics of what the teacher is teaching. Making uke into a 200 pound gorilla who is genuinely trying to break nage's arm (or nage's neck) may be crucial for improving practical skill, given a nage who already has a fundamental grasp of the mechanics. In my case, though, I am not convinced it would help to me to achieve better clarity in comprehending technique.
Most of the practical defensive instruction I've experienced in aikido has focused more on movement and alignment and blending against the rampaging gorilla, rather than trying to execute specific techniques. Sensei is always careful to point out the atemi possibilities, as well as the aikido techniques, that open up once given correct positioning in concert with attacker. The former tend to offer options for a karate-style response, even assuming that one misses or screws up an aikido technique that could otherwise be a good fit.
Modifying your Aikido techniques, if self-defense is one of your goals of training (which I would certainly hope that it would be
as well as cross-training to bring in other compatible techniques (big fan of Escrima/Kali myself) will come if you are conscious about it, but the mindset at least can be part of your training now.
A side point is that ultimately as far a Nage goes-the ultimate goal IMO is to ultimately transcend "techniques" per se and thus, to be in the moment. You will know when these moments occur because you wont recognize what you just did, probably others wont either and if you were asked to do it again you wouldn't quite know how because that response was as unique as the attack. Sure at time a recognizable techniques will show itself without you consciously looking to apply it but the higher level is you don't know what you just did. I guess that would be the Path Beyond Thought. Anyway, I remember Saotome sensei demonstrating a technique at a seminar in Chicago and the Uke would attack say 4 times and there would often give at three distinct responses because he was in the moment and not forcing a technique that wasn't there. He eventually got the attacks he needed of course but the point was profound to me as a young Aikidoka.
This martial mindset is not just applicable to Nage but to Uke as well. It is my belief that a big factor in determining how far we can go in our Aikido abilities is determined by those that take Ukemi for us. In other words, Ukes who give committed attacks, when permissible non-traditional attacks, have an "attacker" mindset you know? They get into their character and play it well! Besides, I've been told that one's Ukemi is the first thing to go so do it with gusto while your body allows!