Why materialists are predominantly materialists

[Bunburryist]

I hope that you are not making the assumption that ALL materialists are philosophical materialists, and not what (I believe) most of are, methodological materialists.

I, for example, do not make the claim, with absolute certainty, that the material is all there is. I am willing to accept that the a material realm (have you defined what you mean by the 'non material' yet?) exists, as long as I feel the belief is justified.

As far as science and materialism is concerned, science operates on methodological materialism, not philosophical materialism. All scientists are methodological materialists, but not all are  philosophical materialists. If they are not methodological materialists, they are not, by definition, scientists.

I guess this would be a good time to chime in on my conception of where I "exist" philosophically.  My interest has always been more in what the average person in society learns to believe in, which is what might be called a "common sense" materialism.  "My body is made of something - atoms I'm told - and my mind happens in my head."  If I'm a believer it might be "My body is made of something created by God - atoms I'm told - and although I may say I believe I have a spirit, I most likely believe implicitly that my mind happens in my head."  The various versions of materialism delineated by philosophers really has no relevance to the average person.  Where as the distinctions made by philosophers might be important in their world, it is nowhere near as important to the world as a whole as the common sense philosophy believed in implicitly by "the masses."  (I may add, by the way, that the common sense philosophy we learn to think in is scientifically informed by teachers educated by universities who are run by academics, and so they are at least partially responsible for this state of affairs.)  I don't think I know one atheist personally who would know the difference of various kinds of materialists.  My interest is in what the average person on the street learns to believe he is.  I think we have to remind ourselves that the people populating a forum like this do not in any way represent the intellectual sophistication of the public at large.