On the contrary, I think virtual worlds will (eventually) be one of the killer applications of blockchains.
People will be more likely to invest real time and money into virtual goods/currency/reputation if they can’t be confiscated by a corporation for arbitrary reasons. The idea will really take off once virtual goods are “portable” between games. At that point you don’t really have disparate “games” but rather a... Metaverse (https://en.wikipedia.org/wiki/Metaverse)
(I don’t imagine all virtual goods will be universally portable. You might be able to bring your CryptoKitties into Second Life but not World of Warcraft, for example...)
This reminds me of the Oasis from the Ready Player One book, where digital currency used in a game gains value enough to replace the USD and other currencies as the standard.
People have been spending billions on in app purchases in app stores for ages. I say it’s all scam, However, that’s the internet economy for you - the value is not in tangible stuff anymore.
If I still had ether, this would be a pretty strong sell signal.