I realize this post is from 2015 - however, I have been sitting here combing through threads to find ones that will help me think through my current situation, and yours has resonated with me. I enjoy watching martial or "balletic" feats of action as much as the next person, but have felt for some time that they represent a necessarily limited subset of aikidoka. I have been training at a dojo which tends to attract a lot of types in their 20's and early-30's, as well as practitioners the next decade up who used to be those young bucks (yes, they are predominantly male) and still retain quite a bit of their athletic prowess. I love to see them train and have learned quite a bit from working with them on the mats, but find their style of practice unforgiving, and not geared to a "longevity of practice" as you aptly put it.
Everyone comes to aikido for different things, and sometimes different things at different times, depending on how long they practice. At this point in my life I have to balance the intensity of my training with having a family. An injury severe enough to interrupt my training will also necessarily impact the time and quality of my family time. Then, too, I find that I value the aikido community as much as if not more than my training. I have had to make changes in training but I hope to keep my aikido friends as I move through life. I love the fact that I may have trained with someone for years and still not know what they do for a living; yet I know their character, their quirks, their habits just from working with them on the mats. My aikido practice may or may not equip me to deal with an assailant on the street, but daily I see its benefits in my improved reaction time as a driver; my ability to anticipate and avoid small accidents; or even just to fall safely if I should lose my footing.
Perhaps others will say my aikido is not "martial" enough. I love what Ledyard-sensei says about aikido as a martial art though, and will quietly go on believing that my reasons for practicing the art are as good as anyone else's.
"So, while I do care about whether my Aikido is effective, and my teachers absolutely maintain that Aikido should function as a practically applicable form of Budo, for most of my students, their lives would not be made one iota better if the could execute that irimi nage against some BJJ or MMA guy or a visiting karate practitioner. I get to see, on a daily basis, what Aikido training can do for people; how it can change their lives, how it can develop their confidence, deal with aggressive personalities, stay centered during crisis, and so forth."