I thought that it was somebody who has recently discovered the existence of
UDP protocol and brags about that to the world, but from skimming the article,
it actually has some non-trivial remarks about UDP and TCP.
BTW, the article's view angle is multiplayer game programming.
This guy (Glenn Gaffer) has been writing network protocols for games for years and shipped popular titles.
On his site you can also find an irate rant about people with no experience dismissing his claims as "reimplementing TCP". It has good points but it's a frustrated rant (reader beware). But it addresses a lot of the commonly believed fallacies.
And he is correct, for "real time" games you must use UDP or you will be in trouble in real world networking conditions. When everything runs smoothly, TCP and UDP work almost identically but when packet loss occurs, TCP will make things worse.
BTW, the article's view angle is multiplayer game programming.