its because nvidia has to accomondate for the low quality psus which are "up labeled";
every decent 550watt psu will run a single gpu/cpu config with oc no problems and since in the steam machine there are no a ton of extra drives/hdds or OC it is enough for this card
Once they have, you'll be able to view a graph of their reputation gained over time.
Here's a preview of what the graph will look like:
No reputation gained yet.