I don't think it makes the argument completely moot, especially for single-player, serverless games like TIS-100. I agree Steam is the most convenient platform out there. If they just took a little extra step to make sure DRM-free games would behave as expected (something like a download link to a guaranteed standalone installer that you can just back up and feel reasonably safe about having forever) in addition to the excellent convenience they already provide, no one could ever beat that level of service. Well, maybe someone could match it and not take 2 weeks to resolve an incorrectly flagged account issue that's immediately obvious to human eyes, then they'd have some competition.