Re: "Traditional budo" and "Fighting art"
Warning, this is probably my more opinionated post yet.
MMA/BJJ folks believe in their training progression because they have noticeable results against resistance. The thing is, I can say the same thing about my aikido practice. When I first started, I couldn't move sandans in aikido around the way I move them around now. I would say that I believe in the/my aikido process for the same reason they believe in theirs. I find myself able to do more and more sophisticated things against people that anyone would consider strong. As I continue my current path of aikido (primarily cooperation) with level-appropriate resistance, I _know_ I will approach the level of resistance that MMA folks would consider "live" and I plan not to be using much arm strength to deal with them (while standing up). I agree it will take longer for me to get there my way -- no argument there. However, I also believe that I will have the chance to test out what I'm doing in certain situations against aikido people who can resist much, much more forcefully and skillfully (in some respects) than I could almost anywhere else - and I don't have confidence I could get there any other way than what I'm doing now. Of course, I'll continue to branch out and try out what I'm doing with non-aikido people too because that is fun and interesting (and important to me) as well. This is, of course, all my opinion based on my experiences.
I do understand the point about a new/newer student getting more confidence in their effectiveness sooner in a MMA setting than aikido - no doubt. I believe that the nature of "live" training is good in that beginners won't really be allowed to be lazy in their training because someone would be all over him like white on rice. Whereas how good aikido beginners (or anyone in aikido) are WAY MORE up to them and therefore it is less likely that they will be compare to MMA/BJJ folks favorably in general.
However, the required intensity of MMA creates a self-selected student base of people who are able to handle that immediately (I see Ron beat me to the punch on this point). The negative side of this is that it becomes a bit exclusive, whereas my teaching/training methodology is less exclusive. I can take people who are not ready for that level of training intensity and give them the room and the support they need to develop to that level (as well as help people who are aggressive practice toning it down a bit). I think these are important points to consider in favor of the Budo approach.