There exists a small but vocal group of negativists, hatemongers, and trolls. Yesterday (and ongoing, just currently out of the spotlight) it was MS, EA, Ubi, et al; Valve just happens to be the target of the day because they're in the buzz.
3 things lead to theft: Greed, Envy, Malice.
Am I pissed? Yup. Do I blame Valve? Nope. I blame the sorry asses who at some point in their lives went astray and think it's ok to steal.