I'm not sure "crap" is the word I'd use for that, but I think I understand what you're getting at. The problem is that the TeX fonts are designed to work at a much higher resolution (as is typical for being printed). They look much better in that case.

Yeah, i don't earn any points for eloquence, but just looking at the side by side examples on the MathML page the contrast is pretty stark. Have often wondered if it was due to low screen resolution so thanks for confirming that. I'll try to be less grumpy the next time I get a TeX generated PDF and maybe even print it out before trying to read it ;o)

I don't see the problem. At that link, the browser column is higher contrast. Switching to the Stix fonts gives characters that look more like the TeX column, but seems to be missing a few things. I did not try all the font options.

Really? Maybe it renders differently for you, because here the difference is stark. People keep using TeX so maybe most people don't see a difference. For me, almost every TeX document seems to use a font that looks like something very old and unprofessional. But perhaps as suggested elsewhere it is optimized for higher resolution output devices.