I agree with you that people are not always openminded. But openmindedness goes both ways – to include being openminded about the fact that some people will simply NOT be as openminded as you feel they ought to be, and they should not be judged negatively for that. Some non-negotiables are very deeply ingrained.
The other examples you cited, are of course extreme ones, and anyone who nixes a shidduch because of the way the father of the boy or girl goes to work, is an absolute fool. Stacked dishes or brought individually – THIS is what people care about? If they really do, then their kids are gonna wait on the shelf a LONG long time. And if people truly feel this way, then it is up to their rabbonim to set them straight about what is really important. I wouldn’t want my daughters or son to have such a shver and shviger who set store by such nonsense. I would question what type of children they raised with such shallowness.