They (BitQuest) advertise the "Stores" which apparently have "some incredible weapons and armor". And they are explicitly denominating in BTC and hooked up to a system for accepting BTC payments.
Both of which seem to fall afoul of the Mojang post.
We are not accepting payments nor selling the in-game currency thus this is not a pay-to-win game or anything outside Mojang's own recommendations for monetizing servers :D
I didn't realize you could buy in-game currency with money. I thought it was a one-way process (mining in game -> bits) used to create a real world value for items in game.
Both of which seem to fall afoul of the Mojang post.