It does seem to me that a lot of people have problems because they're too cautious, but that's not just limited to their remount. I've seen a lot of people in the Master C races who slow down way more than they need to for the barriers.
This was especially apparent with the barriers on the gravel road at Alpenrose. I was blowing past people on those barriers because I was going in as fast as I can run, or maybe even a little faster. My remounts weren't always clean, but I went through so much faster than some of the people around me that it didn't matter. I saw a similar effect with the barriers in the velodrome, but there my speed was limited by how fast I could accelerate ater the turn.
By contrast, at the Blind Date last night, the barrier was set up close to a tight turn and I was barely able to straighten the bike out after the turn before I had to dismount and I found myself losing a little ground on the barriers because I'm slow in tight turns. My remount had nothing to do with it.