its not about irrelevant, its about changing mindsets and acceptance. If Steam can work out of statically compiled binaries, why not use it throughout ? (that's not a question, but a thought) Multimonitor support is VERY,VERY important for a gaming application. So is HDMI. Some games autoscale when they detect a HDMI connection - will you particular distro be able to do that ? If not, then I will switch to a distro that will.

The point is that there is nothing implicitly wrong with Linux as a technology - there is something lacking in individual distros who seem more fixated on IM frameworks than networking/sound/audio/peripherals. For Steam, these are paramount - and this will influence distros.