And I suspect the reason the people on long range UHF do so within spec is because, in my experience anyway, the ham guys get more and more grumpy as you go down in frequency. That video transmitter above operates in the 1.2GHz/23cm band, and no one (around here at least) seems to particularly care too much about it. Going downwards, the UHF (440MHz/70cm) band and the VHF (146MHz/2m) band are used pretty frequently for voice communication, so someone splatting all over the band would have people enraged. Going lower into the HF (<30MHz) bands, you've got people worldwide using those for communication, and they're more than happy to get the FCC or Industry Canada or whatever your local regulatory body is on your ass for breaking the rules.
The more common form of Amateur TV is SSTV[0] - Slow-scan TV. This runs in 3kHz (!!!) of bandwidth and typically gets transmitted on voice frequencies, since it can fit inside the max occupied bandwidth there. People transmit this on the HF bands, which can go world-wide! But... for FPV-purposes, it's pretty much useless. You're looking at something like 8-114 seconds/frame.
But I had no idea that there's people doing Amateur fast-scan TV[1]. That's pretty cool too! I have no idea how readily available light and portable equipment would be for the 70cm or 33cm bands, but there is a bunch of equipment available for the 23cm (1.2GHz) band. As mentioned in my sibling comment... it's not necessarily legal equipment, and it's kind of just... available... from random distributors in China, but it works OK and you're not all that likely to have someone complain about it in that band, unless you happen to be interfering with their attempts to do the same thing :)
I kind of want to pull out that cheap Chinese analog FPV camera too and see how disgusting the spectrum on it is. I have pretty low expectations (camera + tx + rx for $20? yeesh...)
73