Condescension by experts is one means by which bad ideas can promulgate, and lead to bad policy. Everyone you speak with is a potential voter, and at the end of the day, badly or uninformed voters are bad for democratic outcomes.
To go back to your original criticism, asking for background information is a lazy dismissal wasn't a fair assessment. Is wasn't a dismissal but a request for more information. It's important than when you make an assertion that a lay-person might have some misgivings, that you provide some real evidence, or qualify your statement as opinion. An appeal to one's own authority isn't enough, at least it ought not to be in HN, where it would seem many people really care to know more, and want to engage in real discourse.
Edit: qualified some statements..
> conservative bullshit
I think it helps to be mindful to not fall prey to ideology through opposition. Visualizing your interlocutor as an enemy gives no room for either you or them to grow in knowledge, and encourages bad faith dialogue... IMHO :)