I'm sorry, I should probably leave this be, but I'm in a bad mood from the Yankees winning last night.
If you don't have kids you have no idea about kids being 'easier to work with' or how to properly discipline a small child. Priority number 1 is not having your kid run off into a large crowd and number 1a is reinforcing the fact to your child that this is not acceptable behavior, in some cases raising your voice is the only way to properly convene this message to a toddler in an urgent matter. Delaying people entering an attraction for all of the 10 seconds that this took to unfold is not the priority for the parent. If they wanted to have a long discussion on why we don't run off in public, then sure they should step aside and let everyone pass.
I guess I should know better, but it never ceases to amaze me that amount of 'adults' on this board complaining about the interactions with parents and small children around them in the park. If you can't deal with large families and young children around you and all the shenanigans that may ensue, perhaps Disney World is not the place for you.