Properly Understanding The Mesorah

Way, way back when I was still going to the Conservative synagogue in my home town I frequently butted heads with one of the gvirs of the congregation, a genuinely nice guy with a limited Jewish education, lack of insight into how limited it was, and a strong egalitarian streak.  For him it was important that the synagogue be trendy, egalitarian, modern and reflective of societal values.  That's what Judaism was to him and if anyone in the synagogue advocated a more traditional approach (like me) he would go on the offensive.  One day he went as far as to declare, on behalf of the congregation, that ours was a "tradition of change".
I got in trouble that morning for pointing out that a tradition of change strongly suggests no tradition at all.  He didn't like that.
In truth Torah Judaism does allow for change.  Despite what the crowd over at Cross Currents might state the mesorah does shift over time.  The idea that all change is rejected because it's against "our mesorah" is quite false.
The problem is not just when all change is rejected.  It's also when people who believe a "tradition of change" is our tradition also think that the mesorah can be adjusted at will to reflect surrounding circumstances.  So on one side you have "All change is forbidden" and on the other you have "No, you're allowed to change whatever you want if you really have to".
The truth is somewhere in the middle and seems to go like this: change is permitted but only in those circumstances where there is compelling evidence that it's necessary, there is support in the halachic literature for the new position and the consequences of not changing are greater than  the consequences of changing.
Let's look at two examples, one historic and one in process right now.
The first is the founding of the Beis Yaakov school system.  When Sarah Shenirer started the first school it effected a revolution in Jewish education.  While nowadays we take the idea that women should be literate, educated in a broad curriculum and knowledgeable in Judaism for granted it wasn't so long ago that the idea of women's formal education was forbidden, especially in Eastern Europe.  Whatever a woman needed to know, so the mesorah told us, she could learn from watching her mother or asking the local Rav.  She didn't need to know how to read or do math since her role in life did not require those skills.  And at the time the slogan was that it had been this way from time immemorial.  Yet somehow change occured.
Historically it's easy in retrospect to see why this was the case.  At the turn of the 19th-20th centuries Torah Judaism was under assault from all sides.  There was the slow dropping of barriers between gentile and Jewish societies, especially in western and central Europe, gentile societies in which women received formal education.  There was the Haskalah with its challenges to Torah Judaism in eastern Europe in particular.  Finally there was Zionism with its approach to creating a "new Jew", one who could be male or female and educated regardless of gender.  It is quite clear that the leaders of the Torah observant community of the day saw that continuing to pretend that women didn't need a formal education would end up as a disaster.  Women would wind up either being educated in public schools by edict of the government or going off to non-religious Jewish schools run by the haskalah or Zionists and thereby be lost to Torah observance.
A century later the decision to being formal schooling for girls can be seen as an important decision that was made the right way.  But the underlying point remains: the mesorah changed and in a big way.
The second example is the current controversy regarding metzitzah b'peh. As most folks know the new concern regarding direct MBP is the transmission of the herpes simplex virus.  Due to our many sins this virus has found its way into our community on a not-so-rare basis.  Many mohelim are either infected or at risk of infection.  A herpes outbreak is contagious for several days before the characteristic rash appears and the virus transmits skin-to-skin.  All of this is a huge risk for a newborn with an immature immune system.  A neonatal herpes infection could cause encephalitis or death.
There is a way to prevent such things from happening, indirect MBP in which the mohel sucks the blood out of the incision using a pipette or syringe.  There are many poskim who have no problem with this and consider the milah valid if done this way.  It also eliminates the risk to the infant.
And the opposition?  No surprise that one of the biggest reasons for refusing to consider indirect MBP is because it's against "our mesorah".
Now look back at the criteria I mentioned above.  There is evidence that herpes infections in neonates as a result of direct MBP are occuring on a not-infrequent basis.  There is support in the halachic literature for indirect MBP as a valid alternative.  The consequences of continuing direct MBP are newborn boys become seriously ill, possibly brain-damaged or dying.  If changing from direct to indirect MBP is forbidden because "our mesorah" doesn't change then you have to close down every Beis Yaakov as well.
As for women rabbis, well I'm not sure what the compelling circumstances are that demand we consider the idea, there is at best lukewarm support in the halachic literature for such a big change in the structure of religious leadership of the Jewish community and the consequences of not changing are what?