He's right.

There's plenty of great weapons, and most of them are considered that by the public - DA, Blitz, etc, then there's notorious weapons like Acheron and Polaris, then underpowered ones like Winmillion, Shard-type bombs, Heavy Decon, Triglav, CIV, Cautery Sword, and the list goes on and on. And of course we have those weapons which have cool gimmicks but are completely outclassed by other weapons, like Biohazard vs Obsidian Carbine and Cautery Sword vs Tempered Calibur. Then we have weapons which are just plain outclassed by others - Sentenza vs Obsidian Carbine, etc. There's quite honestly very few perfectly balanced weapons, and even those would be outclassed by something.

Basically, SK's weapons are a huge mess.