One of the arguments raised by Rav Tzadok, may he remain healthy and successful, against legitimizing indirect metzitzah b'peh was that the vast majority of poskim oppose anything other than direct MBP and that all contemporary poskim oppose it.
Now leave aside that this isn't true. A significant number of poskim, several of them leaders of their generations, approved of indirect MBP. There are also numerous poskim in both North America and Europe who approve of indirect MBP especially in light of the frequency of herpes transmission as well as a growing fear of governments outlawing ritual circumcision if indirect MBP isn't used.
Here's the biggest question, one born of cynicism and a knowledge of the history of the last 150 years: since the ending of the Sanhedrin around 2000 years ago (may it be speedily reconvened) has Judaism become a democracy in which majority votes rule? Did someone create a parliament? Which rabbonim get to sit in it and who chooses them?
Let's look at the controversy surrounding the definition of death, especially when it comes to organ transplants. There are large numbers of important poskim on both sides of the issue (although just like with metztizah b'peh you'll often hear a proponent for the cardiac death side saying "all the poskim agree with me") but if you expand the eligibility definition I am quite certain you'll find that the definition of death as being brain stem death has far more supporters than the cardiac definition. Should majority rule? Should we tell the poskim on the cardiac death side that their opinion no longer has any authority and that their views are invalid al pi halacha?
Well I'm not going to go and tell them. Any volunteers?
What's more, let's consider one particular issue in which the majority of great poskim were on one side and a minority on the other: fleeing Europe when the Nazis, y"sh, threatened Europe's Jews. Never forget that most European rabbis opposed Zionism and any attempts by their followers to run away either to Israel or America. How many people stayed put on the advice of their well-meaning posek who insisted that prayer, faith and submission to the Germans would save their lives? How many of them actually lived? Majority rule? Doesn't always work.
What's more, we're all well aware of the mishnah in Eduyos that explains why Rabbi Yehuda HaNasi recorded minority and divergent opinions for posterity, because times might arise in which they would be needed to be relied upon. So even if something is a minority position and not accepted halacha the situation might arise that makes it so. Might I be so bold as to suggest that the rise of sexually transmitted diseases present during metzitzah b'peh be worthy of consideration, especially when we're not talking about abolishing MBP but simply adjusting it a little to make it safer while maintaining the fundamental elements of the procedure?
Finally, there is something called Daas Hedyot, as noted a couple of years ago by Rav Harry Maryles. In short, it is the common sense of ours, the unwashed masses. The post noted several instances over the last century where the common sense of the masses turned out to be smarter than the official Daas Torah position. We also know Daas Hedyot has some validity from the Gemara in which Hillel, stumped by his colleagues for how to handle a situation of carrying when erev Pesach fell on Shabbos decided to see what the people coming to the Temple with their sacrifices did. The shomer mitzvos community, when left to its own devices, can often come up with acceptable solutions and this helped Hillel solve the problem.
Well let's use common sense. Ask any reasonable parent whether, given two options both supported by numerous poskim, he'd prefer the one that gives his child a chance at catching an incurable virus that might leave the infant very ill or the method that avoids it while maintaining the requirements of the mitzvah. What do you think he or she will say if not pressured by the local askanim?
And really, that's what it comes down to for us on the indirect MBP side. We are saying we want a safe MBP. They are saying they want to endanger our children for the sake of tradition. Which side does common sense lie on?