Jesus was a Jew preaching within a framework of Judaism which he clearly believed in and claimed authority from.

That framework rejected him, and I can sympathize with arguments that the system of "Christianity" that developed was not the system he intended, but I don't think it would be accurate to describe Jesus as anti-system per se.

Either way, any definition of Christianity that excludes Catholicism or any other organized sect doesn't seem useful.

It's like people defining Capitalism to require pure free markets, just so they can say the US or British Empires never really engaged in Capitalism. It just seems like an exercise in semantics.

> It's like people defining Capitalism to require pure free markets, just so they can say the US or British Empires never really engaged in Capitalism. It just seems like an exercise in semantics.

Not quite as real-world Capitalism has an approximation of free markets. I would say that's quite different from "Christians" going against welcoming strangers and feeding/healing the poor. In my view Jesus was against being judgemental, so sects that prioritise being judgemental cause me some cognitive dissonance when they are described as Christian.