Look at the front page (http://www.reddit.com/r/startups). Most of the ideas ("Apps like Quora but in real time?") are not particularly insightful. And no, these are not ideas with the people-thought-Twitter-was-a-bad-idea defense.
As far as the "Apps like Quora but in real time?" post, it's a terrible title, but actually Google thinks there's some merit to the idea (if you actually read the post), and is trying to execute with Google Helpouts: https://helpouts.google.com/
Additionally, it's sitting there with one single point, which it started with, which is hardly a ringing endorsement by /r/startups.
I mean, you can see a similarly low quality of posts here by browsing new: https://news.ycombinator.com/newest
The quality on the top posts for the day on /r/startups vs the front page is generally higher, too: https://www.reddit.com/r/startups/top/?sort=top&t=day