For last point. Maybe the universities should step up and use that massive administration machine they have build for this publishing. Just post it on one of their websites. Link to the original paper in the prestigious journal.
Regarding you last point: out of interest, what kind of venues were you thinking of? Be this personal blogs of said academics, just dumping it on a preprint server or actual ("formally published") publications?
1. Mathematics is a lot more abstract than it used to be.
2. Mathematics is a lot more specialised than it used to be.
3. Non-mathematical content is inaccessible to those who don't read English.
4. Space in academic journals is too precious to waste on inessential content.
5. The style is part of a universal mathematical culture so you should fit in.
6. There are many alternative places to publish nontechnical academic writing.