This is something I've always taken issue with in line-dancing classes. I have had instructors say things like "hurry up, we have a lot to get to today".
No, in fact, we do not. If even so much as 1/3 of the students are struggling with the skill, drill, or concept being taught then you need to stay with it until they get it. When I teach/taught (firearms or real-world work skills) we don't move on until I have determined that the people not getting it are either refusing to (you can't fix stupid, or arrogant) or are in over their head (snuck/BD'd their Level 01 ass into a level 03 course). At my job I schedule time blocks, not curriculum. We work through the most important skills/concepts first, and we go for two hours. We get to what we get to. Then we come back in a week or two and we do two more hours. Repeat as needed.
So, to expound on what some others are saying here...
The first thing is being able to get the gun out of the holster, in whatever context it would actually be carried. Want to talk about a "gunfighting" class vs. a "shooting" class? that's step 1 to a difference that means something (relaxed accuracy standards, shooting from reverse prone one-handed, and photo-realistic targets do not make a "gunfighting" class). *Maybe* the students should be learning the draw without a cover/concealment garment on TD1 out of 3, but they should at least be using their carry holster. Often you'll hear from higher level shooters "it doesn't matter what holster I use", but you can bet your bippy that it matters when you're new.
The second thing is how to go from the holster, to a good two-handed grip, possibly in positions other than standing straight ahead to a flat target, and get the gun up to eye level. Note that the lessons posted earlier in the thread don't actually say to get a sight picture, they just say to get it up to eye level. If we're worried about 3-7 yards, seeing the hazy outline of the gun in front of the target and firing continuously until the target is no longer in front of the gun isn't terribly hard. Getting that same result "from retention" gets a lot harder.