So, a lot of the pro-speed run responses talk about pulling as much as the party can handle.
When I'm in a random group, I don't know how much that is. I don't know how much DPS the party will do. I don't know how well the healer can heal. All I know is how much I can solo and how things have gone in completely different groups.

I am more than happy to pull fast. I am totally willing to pull big. But I have to get a couple pulls under my belt to see how the group is.
perhaps my issue is that people are just assuming that everyone is "optimized" instead of actually taking time to work with the random group they have.