People.... anyone deserves a certain level of common decency. Respect however is earned... or not as the case may be. I would not advocate respecting nor disrespecting any group of people based on their beliefs. Take it on a person to person basis and see if they have earned and deserve your respect.
Ridiculous ideas do not deserve ridicule. They deserve to be examined and criticized so that people can learn why they are ridiculous ideas in the first place. You don't erase stereotypes, bigotry, or silly ideas with ridicule. You change those ideas and behaviors with education, insight, and knowledge.