I agree that text formatting should be accomplished with Markdown if at all possible. Since Markdown is used across Stack Exchange, there will generally be better support for proper rendering across browsers, mobile devices, screen readers and other accessibility tools, and better compatibility with future systems. MathJax, by its nature and because it is ...
I think the question is too emotionally laden to present the problem correctly. To me it is like "All the preprints use Knuth's computer modern font. How dare we change that?". The use of the word 'abuse' seems to have already not only judged the action, but tried and convicted it, and sent a summons to the executioner.
A more charitable presentation ...
Especially for more complicated diagrams (where it's difficult to draw them using AMScd), a possible solution is to use presheaf website and include the picture into the post. I have learned about this site from Bruno Stonek's answer to How to draw a commutative diagram? (Mathematics Meta).
Advantages of this website:
It is easy to use for people who are ...
This is a community wiki answer made explicitly for testing.
Once typographers are allowed to run amok, there is no way back to normality. For it'd be only a question of time for multi-coloured flashing parts of text, and what not, to start to appear.
Contributions to MO are akin to papers in a journal or chapters in a book, where the editors are free to impose a uniform typography style.
Are there any Markdown MO ...
This is a community wiki answer intended as a place to collect examples of posts and comments which are examples of the described problem. Feel free to add further examples if you find some more. (But let's restrict this to examples where the problem was caused by the recent software change described in the question - not those posts/comments where the ...