It reminds me of when I was in high school having no time to complete my studies, staying up at the community center until all hours, riding unsafe public transportation at night, while not one of the "leaders" expressed any concern. Yes, it was my "choice", but the org highly encouraged a fanatical level of involvement, to the detriment of your own life and responsibilities. Fanatics were praised, promoted, and held in high esteem. If there is really love and concern in an org, it looks out for the welfare of the rank and file members. I don't know if the Japanese cultural template that overlays SGI (and NSA too) is partly to blame, but the org comes across as cold-hearted and uncaring.
Your "experience" (sorry for the cult speak here) pretty much echoes mine. Some of my high school years were a blur, all because of the cult org.. High school coincided with the height of my time in, too. If you couldn't juggle school, a part-time job and activities (literally almost every night of the week and every weekend, including all day Sundays and invariably hours and hours of driving to and from them), you met with guilt trips / manipulation and were made to feel somehow deficient in your abilities, efforts, and subsequently, "faith." Looking back on it all, it was ridiculous insanity. They never cared about me and were openly hostile when you didn't do as you were ordered (err, "asked") by your immediate "leaders." It was this kind of bizarre behavior that alerted me to something being not quite right in the cult org..
It's very interesting to note, though, that when I managed to back off from activities and actually accomplish something in my life, school, job, the cult org. was always ever so anxious to try and rush back in to claim all of the credit for it (cue in grateful zaimu suggestions and friendly stranger "leaders" popping-up with requests for you to do this or promote that). Utterly shameless and aggressively predatory behavior. In fact, sometimes their presumptuous behavior would leave me flabbergasted. Again, more signs that something was off-kilter with both, the people and "organization." In fact, I'm of the honest opinion that many of the so-called "leaders" in cult org., are legitimately mentally ill in some ways.
Its an evil and vile "organization" that eats people up, spits them out and just moves right once finished. The problem is, too many people are only more than happy to let them do so. I'd have to say that it isn't a Japanese quality, rather, it's specifically a destructive cult quality.