I will say I am rather disapointed at the timing on this (although if they sneak in a second perk in addition to gunslinger and patty with this, it'll make me not disapoint, rather 'oh this makes sense, you were using this as a smoke and mirror to hide a sneaky extra christmas gift for us) and while microtransactions do support the developer, I don't like the 'quality' thing, because it turns into 'I spent $10 for piece of **** skins that no one wants' half the time. That said I think there is an option TWI could put in to make it so that this salt goes away and the microtrans truly becomes fully optional for getting reskins, just to speed them up.
Trader Contracts.
These would be free things, that would be hard to do (depending on what it's being used to open, a USB would be easier than a locked crate) and would require the player to do certain things outside normal game play to complete. For instance: As Commando complete a match using the Backup Perk and killing at least one hundred Zeds with your 9mm for a 'moderate' dificulty, or say 'Use an off perk tier one weapon to kill a flesh pound on hard or above' for a hard one.
This would easily get rid of alot of salt, because, now, you don't have to buy the unlock, you can earn it. But the Pay2Open is much, much easier.