I've found that there are different attitudes about photography. Some people just want pretty pictures, and don't much care for what the subjects happen to be. Some other people want specific shots, and I'm in that category. In 47 years of photography, I've never gone out looking for something to shoot. I've always gone out to shoot something specific (air show, astronomical event, family event, concert, whatever). Look at the lunar eclipse picture I posted above. Lunar eclipses are VERY dim. It's just not possible to get that shot without something at least similar to the 2000mm f/7 I took that shot with, using a 15 second exposure using a tracking mount. Now, if you go out, see the eclipse and say, well, I don't have the right gear so I'll just shoot a picture of this lake, then fine for you. But I want the shots I want and I don't want the gear to prevent me from getting them.
I went back for the right lens to get this shot, and it wouldn't be easy to get it without a full-frame fisheye.