What a stupid business decision, now that Bitcoin is booming before Xmas.
Steam should not even be influenced by the Bitcoin price, because purchases are being done through Payment processors. This has nothing to do with price volatility and more to do with politics.
When you use Payment processors, all bitcoins received are immediately converted to fiat. You pay with bitcoin and Steam receive the payment in Fiat. <They do not even receive bitcoins>
If their backend kept the bitcoins and accounting converted it later, then they would have made millions from the latest price surge. ^smile^