It's a generalization to say that all bitcoiners are not friendly in person, as people's personalities and behavior can vary greatly regardless of their beliefs or interests. However, some individuals within the bitcoin community may have a strong belief in privacy and decentralization, which can sometimes translate into a reluctance to engage in face-to-face interactions. Additionally, the online community surrounding bitcoin can be quite vibrant, which may lead some individuals to feel more comfortable expressing themselves in a digital environment rather than in person.

That being said, it's important to remember that these are just general trends and there are many individuals within the bitcoin community who are friendly and approachable in person. Additionally, the community is diverse and encompasses a wide range of beliefs, so it's not accurate to make sweeping generalizations about all bitcoiners.