You do have a very good point.
I'd also like to point out that typically (in any group anyway) new members have very little in common with current members in terms of experience and even in facets of the hobby. The human nature is to work with what is comfortable.
So a thick hide does need to be on both sides (I've been there on both sides). So do open minds.
As long as it is a volunteer organization, usually, formal training or mentor programs do not exist. They should but do not.
One of the best programs I've seen is the Friends of the C&TS - there is an attitude of let's come together and save what we love. I am sure there are some politics in the Friends (all groups have it), but compared to many, it seems to be a minimum.
I've not seen that sort of attitude in many museums.
Doug