The hat fits me, and also it would fit older users . Everybody ages, and with age memory is not the same, particularly short term memory. I do try to use dollar signs around simple formulae, (since I found out that two $*$ in the paragraph turn everything into italics and destroy the simple formula ! ). The same care I take in spelling and syntax. (syntax sometimes is atrocious in some questions).
I use simple math and / and x and ^ . When more complicated formats are needed I use screen shots. I am grateful to edits for replacing screen shot formulas, even the simple small ones, (I guess people gain points by doing that).
The effort for remembering a new format grows with age.One of the reasons I participate here is to keep my physics memories alive, and I enjoy the effort. I do not think format is all that important , these answers are not going to a publisher to become a permanent book. If physics.SE wants to stick to format as the mathematics.SE does, it should be clearly stated.
Edit after comments:
I made the last sentence in bold.
In a comment blind and people with difficulties in vision were mentioned ( also older ones) where using mathjax would enable them to magnify the formulae in a tablet or screen sensitive device.
It would be interesting to see how many users of physics.SE consider themselves in this group. In my case, resistance to mathjax is accompanied with resistance to newfangled screens where not so steady fingers have to manipulate tiny areas.
It is the same as resistance to new cars, with oodles of electronics, give me a gear shift one any time. All of these new things need a lot of memorizing, motor memory too.
So I can just promise to use the dollar signs for simple expressions, and give links for any screenshot formulae I use. If mathjax becomes a rule, too bad. I will have to look elsewhere for my physics fun.
I thought this coincidence interesting:
Just saw on TV a young blind boy on the fourth year of a physics course in Thessaloniki university who won a summer student place in Oxford for astrophysics! the link is in greek. Last year he had won a place at MIT ! He plans to go for a PhD in the states. His professors talk of an exceptional mind. It seems there are computer based tools which can transcribe books to Braille.