It looks like you've expanded your post after I replied, so here's an addendum.

Moreover, I am curious as to the source or cause of your enthusiasm for LaTeX on Less Wrong. A lot of people here are in the habit of reading the output of LaTeX (printed on paper) since it is used for most math papers and many (most?) science papers. I suppose you are one of them; aren't you? Are you also in the habit of writing LaTeX?

I'm used to reading and writing LaTeX, yes. The source of my enthusiasm for it comes in two parts:

1. Because occasionally I want to be able to write math in comments, and the LaTeX syntax for this is the least horrible (and most widely known) that I know of. Simple ASCII formatting is better than nothing, but only goes so far.

2. I'm sure other people would also like to be able to write math in comments, with formatting that doesn't suck. For my part, I would like to be able to read their math with decent formatting.

Pretty straightforward motives, I would think.