Maybe he wants to sell it for bitcoin because he wants to invest his earn money in bitcoin and he is it more profitable if he invest with it. Or he want o get the deal close immediately so he can get and earn the money without using broker other angle i see there is he is addicted to bitcoin thata why he sell his house so he can have invesment or to gamble.
The only thing with Bitcoin is that you cant predict but making in an investment in a house is the best investment that you can make with Bitcoin.
A house will never reduce in value so you can even earn some profit if you are selling it !