The main reason I've "nearly quit" and just do about a dozen jumps per season:
> I think my DZ has about the most friendly atmosphere possible, but I lack the social skills and energy to integrate properly and make friends so as to get into two-ways and beyond. This is made worse by the fact that I don't go to the DZ very often (not every month, by any means) and so am not a regular face there. Solo jumps got boring by about my third one and I just have no interest in them at all, but most times I go I end up doing three solos and am completely sick of jumping by the end of the day.
> I don't have my own transport and I rely on lifts from instructors or other jumpers, and I'm a bit uncomfortable with that arrangement. Also, my availability/motivation often doesn't match theirs, so if I miss the one week in six that I feel like a day at the DZ, because I can't get a lift, then the opportunity has passed.
> Cost... to some extent. But it's not a huge problem. I could afford a great deal more skydiving than I actually do... but I guess I just don't like it enough to want to spend more on it.
>... I just don't like it that much! I rarely check this forum any more, and don't think about jumping when I'm not there or about to visit the DZ. Maybe I'm "doing it wrong" etc. but ultimately I don't find much pleasure in it and the whole act is fairly boring to me. I get a lot more pleasure from other hobbies which most people would think are extremely tame and uninteresting - because I can engage with them more, more often, and for longer at a time. Skydiving is physically limited in this regard. On a nice sunny day there are several places I'd rather be than at the DZ.
This is also no doubt related to some of the other points above, and they all feed into each other.
*shrug*
It's not for everyone.