I understand your frustration, but you don't need to attack me about it. I have my own frustrations about the platform. But the fact is, the versioning is a contract:
Where A is a major version (basically) guaranteeing compatibility with plugins that are compatible. number changes here are most certainly breaking. Anything at 0 should be considered unstable.
B is a minor version change, and number changes denote possible breaking changes (under 1.x.x)
C is bugfixes, but compatibility with dependencies.
Xenoforo is at 1.5, and has been around for much longer than NodeBB