From the blog post:
Historically, the value of Bitcoin has been volatile, but the degree of volatility has become extreme in the last few months, losing as much as 25% in value over a period of days.
Bitcoin had a plenty of 20-30% drops and spikes this year and the year before, it's simply not true that volaility has increased, unless they measure volatility in flat amounts, which is dumb.
I've personally used Bitcoin 2 times with Steam, and to those who don't know how it works, they actually have Bitpay as intermediary, and Bitpay requires transactions to be sent and confirmed within 15 minutes - so the chances of BTC dropping 20% in 15 minutes are actually extremely small, and all the volatility is handled by Bitpay. The real problem here is that customers have to use high fees to get their tx included in the next block, otherwise Bitpay will have to send their transaction back.
You can't compare the volatility now with the previous years, because of the huge price gap!
Major currencies average between 0.5% and 1.0%.
And this is the volatility of BTC in US dollars per 30 days in 2017. You see the "problem"?
https://i.imgur.com/LdAZLRY.jpgThere's no huge price gap, volatility is measured in percentages (just like on your chart) and not some flat differences in price.
And why did you choose such a small time frame, completely ignoring all historical data?
Here's how it actually looks like:
So, while volatility in this year increased in frequency compared to 2015 and 2016, it's amplitude is way lower than it was in 2010-2014, and it seems like the general trend is that volatility will be decreasing in upcoming years. And again, this is not a problem of Steam, because it's all handled by Bitpay, Steam was never receiving any BTC directly. And by the way, it means that not much has changed actually - people can deposit BTC to BitPay or Xapo accounts and spend those funds on Steam or any other place that accepts credit cards.
Volatility is usually measured daily, monthly, annually and throughout the lifetime.
Is not as simple as looking at the % value and say it is more/less volatile.
You can't take the standard deviation of a fresh currency like Bitcoin and measure it yearly against a fiat(USD) , and say look btc was more volatile before because the amplitudes were higher.
As shown in your chart.
The higher the value of BTC/USD the more each % deviation count towards the weighted average . When BTC was 10$, a standard deviation of 10% monthly wouldn't have yield much to the weighted average.
However at 15000$, 3% volatility is way off the chart compared to when it was 10% at 10$.
Thats probably how Steam financial team based their decision on, and why BTC is extremely volatile now.