FIFTY MINUTES
YOU CAN'T MAKE ME WATCH IT ALLLLL
I'll listen to the whole thing in the background, but from what I've heard so far:
He's complaining about the dead ringer being OP, a must-use weapon, and one that takes away from the fundamentals of the spy class. Obviously, he's talking about pubs, so I took that in mind with this thought, but: What really strengthens a class is its mobility. It can be used as a tool for engaging, a tool for disengaging, and helps to complete objectives in classic gamemodes such as 5CP, CTF, and AD. For spy, being able to cloak on demand is his form of mobility. His invisibility helps to complete all three of these things. Dead ringer does not give you a tool for engaging (even if you use it to go in, they now know of your presence and render you useless) and places a time limit on your disengagement tool. But is it a better weapon for deathmatch? Yes of course, but the tradeoff you are receiving is losing mobility in exchange for power, a tradeoff used on many items in TF2. Is the go-to strategy in pubs deathmatch capability? Perhaps, and if so, that is not at all the fault of Valve and is why comp scenes have banlists related to their mobility-based metagame. If deathmatch-assisting items were truly ruining pubs, server owners are given the capability by Valve to restrict the items they choose. Weapons cannot be balanced for every possible metagame and format at once without giving up on diversity, another dimension of game design altogether.
So his point isn't really valid.
EDIT: And now he says the spread cones on shotguns are too tight. Lol.