Yes, exclusivity is never a good deal for the end users, but it often enables a quicker development cycle if the developers are able to use third-party multiplayer libraries like Valve's Steamworks. It's a tradeoff. If the developer is dumb/lazy enough to accept this tradeoff then that is their problem. It only hurts their product, not the industry.
And this is coming from Gearbox? I have little respect left for Gearbox at this point. After their totally broken PC multiplayer in Borderlands, it's clear they do not understand PC games. Maybe if they had used Steamworks to handle their multiplayer, Borderlands multiplayer would have been playable.