Is There a Point to Orthodox Unity

At this time in history, the Orthodox world can be divided into four basic groups:
1) The Chareidim, or Ultra-Orthodox
2) The Dati Leumi or Mizrachi or National Religious
3) The Modern Orthodox
4) Chabad-Lubavitch
In theory, all would agree that unity amongst the various Torah-observant groups is a critical thing. However, as Homer Simpson once poignantly opined: "In theory, communism works."
As the old saying goes, it takes two to tango. Unfortunately, when one gets past the wistful "Wouldn't it be nice if we could all get along" stage, there are very few partners at this dance. In fact, I would go so far as to say that while groups 2 and 3 are interested in taking practical steps towards Jewish unity, groups 1 and 4 are not and to think otherwise is sheer naivety. Given all that, I wonder if there's a point to even pretending that it's a possible goal.
How can I be so cynical? It's easy when one looks at the underlying assumptions of each group. It then becomes quickly obvious that dialogue and attempts at rapprochement are a waste of time.
Consider, as a first example, Chabad-Lubavitch. Although many of them will publicly deny it, and certainly others who are afraid of the implications of it, the movement has elevated their departed Rebbe to the level of a demigod, if not higher. This belief permeates everything they do and serves as their basic motivation. It also sets them apart from the rest of Torah Jewry, even other Chasidim, which rejects this philosophy as either tantamount to or an actual form of avodah zarah. Having set themselves apart, Chabad also believes that its belief in a supernatural Rebbe is a core Jewish belief and that not holding this view is like questioning the Jewishness of Shabbos or kashrus. Thus, in terms of groups 1-3, there can be no meaningful dialogue towards Orthodox unity. After all, the only way to get Chabad to cooperate would be to accept their Meshichist beliefs which is not something an observant Jew who is not a Lubavitcher is likely to do.
Then there's the Chareidim. Like Chabad, they have certain core principles that are non-negotiable. Unlike Chabad, they're not potentially heretical. In fact, the core underlying principle of Ultra-orthodoxy today is quite simple: Proper Jewish observance and being Chareidi are synonymous. Any other form of observance falls short of the ideal and the authentic and cannot be portrayed or treated as genuine Orthodoxy. This attitude precludes unity with the other three groups. For Modern Orthodoxy and Mizrachi, it would mean denying the legitimacy of their entire philosophy and practice. For the Chabad, it would mean having to abandon their Rebbe-worship.
It is also interesting to note that neither the Chareidim or Chabad express any real interest in furthering Orthodox unity. Indeed, the message from each community is: When you're ready for unity, we'll be waiting here for you to join us. This is hardly encouraging.
This leaves the two groups in the middle, Modern Orthodoxy and Mizrachi. The problem is that both groups are currently struggling with existential defects that betray any efforts they might make to portray themselves as viable Orthodox alternatives for people looking to be Torah observant.
In the case of Mizrachi, the obsession with the plight of our brethren in Yehudah, Shomron and Aza is the major factor. When one sees a black hat, one thinks of Torah observance. When one sees a large knitted kippah one thinks of "settlers". The idea that the latter are just as fervent in their observance and learning as the former does not occur to many, a direct result of the failure of the Mizrachi movement to remain true to its principles in terms of promoting Jewish observance in Israel.
As for the Modern Orthodox, as mentioned on this blog many times before, what exactly do they stand for? Who represents them? Rav Hershel Schechter or Rav Avi Weiss? Is it intellectual orthodoxy that defines the movement or "open orthodoxy"? Without knowing where they stand, how can the movement go forward?
In the end, assuming Chabad continues its slow tailspin into heresy and a schism with the rest of us, it will be the Chareidim who wind up as the dominant, defining force in Torah Judaism and eventually the rest of us will be provided with a choice. Join them or being considered non-observant. Unless a viable alternative can be created. Unless.