Perhaps because they didn't try to excommunicate the disbelievers. They simply waited for them to die off.
People really like this idea of old scientists just dying off as a new paradigm comes in. But frequently old people don't have trouble adopting the new paradigms. When Einstein proposed special relativity, it didn't take a generation to get accepted. Similarly, it didn't take very long for the double helix or the triplet code to get accepted by biologists. To be sure, there are exceptions to this trend. One prominent example is Joseph Priestly who despite being responsible for the experiments that discovered oxygen and paved the way for modern chemistry until his dying days continued to defend phlogiston theory. But he's the exception rather than the rule. Others of the same age as Priestly embraced the chemical revolution.
(Incidentally, this is connected to why I don't like the common LW tendency to use phlogiston as an example of a bad hypothesis. In its original forms it worked. Others rejected it precisely because it had been falsified. The vague, convoluted form of phlogiston that is discussed here was the consequence of seeing the theory handed down after already being intertwined with Priestly's convoluted defenses from the last few years of his life.)
The upshot is that scientists very rarely need to wait for the old ones to die off.
People really like this idea of old scientists just dying off as a new paradigm comes in. But frequently old people don't have trouble adopting the new paradigms.
This post grew out of a very long discussion with the New York Less Wrong meetup group. The question was, should a group dedicated to rationality be explicitly atheist? Or should it make an effort to be respectful to theists in order to make them feel welcome and spread rationality farther? We argued for a long time. The pro-atheism camp said that, given that religion is so overwhelmingly wrong on the merits, we shouldn't allow it any special pleading -- it's just as wrong as any other wrong belief, and we'd lose our value as a rationalist group if we began to put status above truth. The anti-atheism group said that, while that may be true, it's going to doom us to be a group exclusively for eccentric nerds, and we need to develop broad appeal, even if that's hard and requires us to leave our comfort zone.
Things got abstract very fast; my take was that we need to get back to practicalities. Different attitudes to religion have different effects on different types of people; we need to optimize for desired effects and accept what tradeoffs we must. We can't appeal equally to everyone. So I came up with a sort of typology.
The Four New Members
Annie