Well we could found a "Bitcoin" Nation
Such a nation exists, it's called "humanity"
Does not compute.
In order to be a citizen of a nation you must first be associated with it, most people never heard of bitcoin let alone own some.
Added to that a nation serves more purposes than those bitcoin itself provides.
A bitcoin "nation" would require additional infrastructure like consensus based decision making for example using merged mining proof of work voting. Some database on personal details like contact, ownership of certain things like land or physical infrastructure and so on. Most of these would be very rudimentary since it would most likely be a decentralized republic, but nevertheless it is necessary.