No, I'm not wrong. These practices didn't start in force until 360 realy started pushing them. Prior to 360, most minor DLC like map packs, were free, with the occasional dev charging for more involved DLCs, and then most eventually became free after a while. MS advertized these minor DLCs in such a way to make them sound like a spectacular deal, and people fell for it.
The same thing happened with paying to play online. Prior to 360, the only people that paid to play online were some MMOers. Now Activision and others are trying to move to the same business model across all platforms.
All because people fell for the tricks, and decided that it was OK to pay in the first place. If nobody would've bought Gold, it would have become free, just like it did on Windows Live. Same goes for the map packs. If people would've refused to pay for them on 360, they would've been made free.
Sorry, but the pay to play model was first really pushed by MS on 360, and it is currently ruining the entire gaming industry with this new found revenue source. It wouldn't be so bad if these were real value added items, but they aren't, they are just new charges on the same shit we've been getting for free for decades.
As for Half Life, Episode 1 and 2 are not DLCs. They are standalone games. They were shorter, so they sold for less per game. Seems fair to me. Less content, less price. That's a fair business model. Not this shit where I pay $15 for a map pack the day the $60 game (with less content than it's predecessors) came out.
Short version = like it or not, the 360's business model is having a detrimental effect on the consumers of the gaming industry, period. We now pay more for less.