Charging for the map packs is the 100% smart thing to do, otherwise no maps will be released. They have to pay for the time spent making them some how. And besides CoD doesn't punish players who dont have the map packs, it shuts off the possibility of those maps coming up for that player's party. if you join in session those options are not set.Now with Brink, because the storyline is played both single player and multiplayer the whole storyline changes with each new map added. meaning that The multiplayer is the exact same thing as the singleplayer.
Not to mention the fact that so far all the Borderlands DLC's that have been released have added in entirely new sections of the game altogether it wasn't just 'hey lets add a new map' it was more 'Hey lets put in a second storyline altogether' doesn't compare with CoD now does it?
Valve doesn't just 'give away' map packs either, i've spent my fair share of money for the DLC on the Left 4 Dead series, now that was a complete piss off. There was absolutely nothing of value in any of those map packs, so what it added a new map that i would play once in a while because i was one of the only idiots stupid enough to buy it. the 'new maps' on those games were litterally the same thing as the original maps, they just looked different. That same thing goes with CoD, all their map packs add nothing of any real value to the game, only a new map to play on once in a while when everyone in the lobby has it.
What?! Have you even PLAYED the DLC for the L4D games on a pc? I don't think you have because it's MICROSOFT'S fault that the DLC costs money and ONLY for the 360 users. All that has been for FREE for the PC users. As for all the maps for Team Fortress 2? User created or Valve created, it's all been free. Valve wanted to give the DLC for the L4D games away for free, they even wanted to do the same for all the updates for TF2, but they were told by MS that you must charge money. That's exactly why none of the updates for TF2 have been released for the 360 and they still feel a bad because of that but there's nothing they can do.
Now in TF2 you can donate money (you get a hat and stamp that appears on the hat for showing your support to the developer) to the creator of the maps now, and each stamp only costs 99 cents, and you can buy as many as you want. But that's all optional.
As I said, there is NO logical reason to justify charging $15 for 5 maps, at least 2 of which are from previous games. That's just Activision taking advantage of it's users to mine them for more money. And Valve's stance on maps is they will never charge money for maps for the PC (as I stated, Microsoft had their hands tied but they've found a way to sneak around any issues like that with Portal 2 for the PS3) because they feel that for their players to play new maps together, they should not force them to pay money unless it's in the way of an optional donation. They had special hats for TF2 to donate to Japan to help Japan out, one even being $99. People have paid that much for a cosmetic in game item because it was completely optional.
And You missed the fact that I stated that the new "maps" in Borderlands are expansions. If Brink decides to charge for maps, I hope they choose to mape the maps expansions to the game like Borderlands did instead of going the CoD route and just charge maps that are mere settings to play in.
And for L4D's DLC, those are new campaigns, they are all different. Granted you do the same thing in each, go from point A to point B, but are you really telling me that the Passing and the others aren't new experiences? And as I stated, if you had gotten it all for the PC, they would not have cost you a single cent. It's Microsoft's fault you had to pay money on the 360 for the campaigns, so don't try and pin any of that on Valve. They could have done exactly as they did with TF2 and not given 360 users any of the campaigns at all.