[INFO] Steam just increased market listings and Max wallet

You of course can, yet you shouldn't imo.

As to your example, I'd blame the junkie and I actually do. I won't blame someone else for another's person poor choices (in this case to get addicted). The smugglers are to blame for the smuggling and selling process and they should be punished accordingly, yet I don't see it as their fault that someone got hooked.

The fact that skins were created and used as a free content in a prequel means nothing to me and so it does to them. They saw the chance and they did monetize it. Nothing unethical here. What I can blame Valve for, is that even though they did create an in game transaction system which seems to earn them a lot of money, they did put a price tag on the game. It should have been F2P.

EDIT: What's unethical is that they have people create skins, yet those people don't get any of the profit (AFAIK if I'm wrong, feel free to correct me).

Skins were never free. Sure you could change files on your end and see whatever skins you want to see, but you cannot show them to others, so its moot. Its like comparing single player RPG like Skyrim to an online MMORPG. Most people would prefer to get a cool item drop in an online game that they can share and show off to other people than a single player game, where you can just cheat/hack/modify files to get whatever you want.

Steam as a platform is currently based around the concept of sharing. When I get a level on my uplay account I dont care because I cannot share that level with other people on my friends list. On Steam I can show this number around, and even if it does not mean anything, people like me spend money to get it higher.

Market is actually an awesome idea. While I agree that 10% cut seems a bit too much, but aside from them, no one else setup any infrastucture that could do this. Now I can play a game, invest in it and cash out when I am bored of the game and invest the same money in another game instead. I did that with Spiral Knights. I sold whatever I had on my account and with trading and market it ensured that not all my monetry investments were lost.

Basically there was a need for a service and Valve stepped in and provided it. Since there was no competition they can get away with charging 10% fee even if the same item gets traded 10 times. You might argue that its a bit costly, but the service itself has merit.