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.