Honestly, anyone pining for all the features of XML probably didn't live through the time when XML was used for everything. It was actually a fucking nightmare to account for the existence of all those features because the fact they existed meant someone could use them and feed them into your system. They were also the source of a lot of security flaws.

This article looks like it was written by someone that wasn't there, and they're calling people telling them the truth that they are liars because they think features they found in w3c schools look cool.