If I write \underset{x\in A}{\mathrm{sup}} in $\TeX$, it looks like this: $$ \underset{x\in A}{\mathrm{sup}} $$ If I write \sup_{x\in A}, it looks like this: $$ \sup_{x\in A} $$ The latter usage, besides being simpler, has other features that the former lacks contrast this:
a \underset{x\in A}{\mathrm{sup}} b
with this:
a \sup_{x\in A} b:
$$ a \underset{x\in A}{\mathrm{sup}} b $$ $$ a \sup_{x\in A} b $$
The latter standard usage provides spacing before and after "$\sup$" and the former does not. Simple standard commands like these are intended to make it unnecessary for the writer to attend to such things.
When I see something like the former usage in a posting, and change it to the latter, and point out all of the above in a comment, often the poster has thanked me for informing them of features of $\TeX$ that they didn't know about. None of them has ever complained after I did this. But here I find Michael Greinecker saying I'm "imposing [my] aesthetic standards on others" by doing this (the example he was commenting on was exactly the same two bits of $\TeX$ code you see above). He didn't say whether he'd apply the same comment to spelling corrections.
Is informing people in this way of standard $\TeX$ features that they didn't know about a bad thing?