I don't see why the questions should be obvious, there simply are no stupid questions and if someone asks a question they deserve an answer, not an automatic upmod.
Comments like 'citation needed', 'prove it' are fortunately rare enough on HN that it's not a big problem.
I find many times I've asked questions related to an article that someone involved closer in whatever the topic of the article is could answer I have got up votes but less often answers. I guess it's a form of me to, others interested in an answer to but have nothing to add will up vote.
Comments like 'citation needed', 'prove it' are fortunately rare enough on HN that it's not a big problem.