That is not what OP was saying at all. I don't know what hypothetical person you're quoting. OP wasn't even talking about any solution. Just stating that the source of the problem isn't that complicated. Sometimes a simple problem has a complicated solution.
Nobody serious is asking for all the Israelis to leave. The solution to one ethnostate is not another ethnostate. We're asking for a new state that truly treats all its citizens equally. And to have a tribunal of sorts to convict the people who committed war crimes. This is not an easy solution, but getting justice rarely is.