Mostly what Devious said, but it's not a networking development issue, we already have our own networking in place. The bigger issue is that with ie. GOG we'd have to reimplement their version of the remaining Steam API, considering friend lists, server lists, achievements, update rollouts, etc. for a second time. Right now we've got a system in place that works, and at least while we're still rolling out regular updates we're not doing so on 2 different platforms.