A bitcoiner is someone who
- measures his whole wealth in BTC
- war against fiat and KYC
- promotes self-custofy
- permanently studies it in an holistic manner (libertarian)
- rebel against the system
- supports open source / freedom tech
- think about it at least 6 times a day.
It's basically an activist that promotes Bitcoin as a movement, rather than just an investment or tech.
His BTC bags would probably be used to protect and make Bitcoin unstoppable.
We are probably a couple of thousands in the whole world.
The alternative is just being a regular BTC investor. Most people will fall in this category.