Looks like the article argues that because WireGuard tries to do one specific thing and do it well, without doing all the other things - it is doomed to fail. Unlike all those other technologies (IPSec, OpenVPN) that do a gazillion different things and are not even supported as a standard across the various operating systems and vendor devices.

Idk, seems like someone is trying very hard to defend their solution by vaguely throwing empty criticism about a new technology. Not even very convincingly.

From time to time someone can write a critique about X that actually touches on the bad parts, but this article is not it.