Two things that are tangentially related to the topic.
First off, lots of Valve hate everywhere I look, which begs the question why people who hate Valve are using Steam. Buy games off Desura. Get physical copies of games. If you're buying game's on the extremely convenient platform that Valve has made, it kinda undercuts your moral high ground. It doesn't matter if the games you want are only on Steam; by using Steam, you're implicitly supporting the business practices you so ardently despise.
Second, the paid mod update was accompanied by Skyrim going on sale, so I got Dawnguard and Dragonborn for 66% off, and, since I've stopped giving a shit about paid mods and am just waiting for the dust to settle, I'm happy about that.
Maybe people in Europe or North America can afford to buy games in Desura or GOG, but in my case that is just not possible. First because I'd have to pay in dollars (and the exchange rate is currently US$1 = R$3, not counting any fees for the conversion), while Steam allows me to use local currencies. Retail rarely has stuff I'm actually interested in, and when they do it's incredibly expensive due to a 70% tax on (physical copies only, fortunately) software.
So I only have three options: I can stop playing games (no), I can use Steam, or I can pirate.
Boycotting is just not an option for some people.