What do you mean "Leave behind" Judaism!?!? Some of us Messianic Jews proudly lived in the shtetls and kept kosher for two millennia, alongside our brothers, the Sons of Jacob and Judah, despite the oppression and suppression by the Christian Church.
That's why I don't identify myself as a Christian. While by the strictest sense, I suppose I probably am, but "Christian" has a connotation of people who abandon most of the mitzvot, who are not Jewish in any sense, who give up the ordained High Holy Days, and so on. And that's not me.
Do I believe Yeshua was the messiah? Yes. Does that make me cease to be a Jew? I and many generations of ancestors say no.[/offtopicness]
Back onto the topic - I agree that Christians need to cool off a bit about the differentiation between sects. I know in my synagogue, the newer Messianic - that is, people who they themselves or their parents became Messianic from Orthodox, Conservative or Reform Judaism - tend to get caught up in that too. They tend to question as to whether various Christian denominations are saved - especially Catholics, Mormons, Orthodox, (Hashem)'s Witnesses, and the more conservative Protestant denominations. This hostility toward Catholics, for this and other reasons, was enough to effectively force me to break off a relationship with my Catholic girlfriend to avoid alienation by the community. Of course, that wasn't all of it, since HER community was close to alienating her for considering a relationship with a non-Puerto Rican non-Catholic, but I digress.
My point is - I agree. People need to stop trying to divide a faith which Messiah brought together. The point is salvation through Messiah, and nothing else. All other differences in tradition are just that - differences in tradition. While tradition matters deeply, it should not divide people.