Rickenslacker
Banned
First of all:[TF2 rant]
From Dust mask is a Demoman item, the Deus Ex arm is a Heavy item, so you wouldn't find someone attacking you with both on.

Other than that, it's a fair point. There's definitely more added complexity to the game due to the new weapon additions. The general strategy to approaching some classes have completely changed depending on their gear, and I'm always a bit paranoid when I take out a spy. However the reason you'll find people don't throw a shitfit over weapons being a certain price at the store is because they are worthless in the trading market after a couple weeks of being introduced, so they're very easy to get for free or in a random drop.
Not to mention a lot of the new weapons end up being extremely gimmicky or situational. The Cow Mangler rocket launcher that you mention is pretty crappy compared to the stock rocket launcher. It may have 5 rockets and infinite ammo, but it reloads slower, does less damage, does awful damage against sentries, and has no crits, besides who the hell runs out of rockets anyway.