I read the article, and actually retweeted it. I think there's a lot of merit in that view. In a representative democracy, the legislators are expected to represent their constituents and do some hard work. This is not constitutional, and so it's not required. It then becomes a political and normative judgment.
Their article was important in suggesting how complex issues can be easily hijacked in systems that appear more democratic but in the end are actually not. Asking people to leave or remain when there's so much misinformation is highly problematic. The investment in public education ought to be pretty rigorous.
I'm very comfortable with their general conclusion that direct democracy doesn't necessarily mean greater democracy. There is a place for referendums, but equating referendums with the quality of democracy is probably a mistake.