Why isn't the price of BTC rapidly growing due to WannaCry? This occurred to me today: the ongoing ransomware attack (started on May 12) caused by the WannaCry virus infected over 230 000 computers so far (source: Wikipedia). This probably means that a lot of these people (and/or companies) will pay the demanded price in Bitcoin, which, intuitively, should lead to a rapid growth of BTC value. 

However, as it can be seen in the image below (BTC-USD chart taken from Kraken), this isn't happening. This is slightly confusing, so I'm looking for an explanation.
I've read somewhere that around $6000 had been paid in total; at roughly $500 per ransom that's 12 people who actually paid. That's a speck in the ocean.