This. It's not like they just turn the thing on and let you start hucking. For liability and all they have to have coaches there. They will make you go through a minimal progression before you can start doing inverts/corks.
FYI, try to figure out how to self correct on the bag the first few times you straight air on. I haven't hit it yet, but have watched a bunch. There is a hole that forms in the snow where everyone slides off the pad. They do their best to keep filling it in, but a there have been a few concussions from going into it head first and it looks like you could easily separate a shoulder. Try to figure out how to spin around when you fall on the bag so you get your feet below you.