I think a better question to be asked about Robert's vote, rather than criticizing directly, is why.
I personally have not tried Overwolf in any game, so I would like those who have and/or are in favor of its implementation to inform us of the possible pros and cons, should it be ported to SA:MP.
Just to be clear: this is not something argonath has to implement. This is a game-overlay which users can install by themselves. It's now officially supported by teamspeak as well.
The main functions are: Teamspeak, Skype, Webbrowser, Facebook and recording right ingame. Also GMail, notepad, calculator, music player, IRC, and GTalk are supported!
Downsides? Not that i know of. Some higher RAM/CPU usage but that should be it. Haven't seen a lot of fuck-ups in supported games that i played.