Emanuele Viola is relatively famous in theoretical computer science, so he's definitely not a crank.
As far as TeX goes, Wordpress has a long way to go in terms of offering good native support for any TeX variant, so it's understandable that one might try to avoid it in that context.
I'm using LaTeX for Wordpress (https://wordpress.org/plugins/latex/) and it seems to do the job. However I agree that it's pain in a to find proper plugin and set it up and even more so if you ever want to change to some other plugin. For a platform that is a major writing instrument, it's a pity to be in this state.
Source: I've been using Wordpress to blog about math for over three years and have had a small amount of (indirect) contact with the Wordpress devs. Apparently they are considering alternatives to their current setup which renders tex formulas to images.
As far as TeX goes, Wordpress has a long way to go in terms of offering good native support for any TeX variant, so it's understandable that one might try to avoid it in that context.