When you first sign up for OW classes you assume that everyone connected with the dive shop are knowledgeable and excellent divers. You assume that you will be trained to the standards of a competent diver and that you will be sold the correct dive gear.
YOU might assume that someone who is licensed and trained in a particular vocation is competent at that vocation. I don't. In fact I assume the opposite until they prove otherwise.
You will have learned that snorkels aren't needed for diving and you may realize that all of the equipment that you were just sold could be bought much cheaper elsewhere and in many cases that the equipment that you were sold just weeks ago isn't the equipment that you now wish you had.
Snorkels have their place in diving. As an emergency piece of gear when you've got a long surface swim, or to utilize "free" surface air when swimming along the tagline from the stern to the anchor line at the bowline to save 300 psi for your dive, or for when you've got to hang at the surface and you'd rather be floating face down and looking at the shallow reef below you..to name a few.
You will then realize a few weeks after that that retractors are a joke as well. You will get tired of buying tank lights for night dives and will buy battery powered ones found at the dive shop. Soon you will wonder why in the world are you using tank lights.
I am going to "assume" as you do all the time apparently, that a nonbattery tank light is one of those luminescent "snap away" lights that glow for an hour or so. They're a waste of money, bad for the environment, and there are long lasting battery lights that are much better for the task. Guess what? They're called "tank lights" too!
And this is not something normally covered in a basic OW course. It's like saying that when you get your driver's license you should be taught all available options for your automobile.
Regarding retractors- I have my dive light on one, and my compass/slate on another. They fit neatly in my BCD pocket and when I want either one, I simply pull it out and use it. If I drop it, it doesn't fall to the bottom of the ocean, it's right there at the end of my retractor. I also use a retractor to keep my inflator hose close to my BCD so it doesn't drag on the bottom. If I was using a gauge cluster rather than my AI wrist computer, I'd have that on a retractor too, so I don't have to unclip the thing every time I wanted to read it, and it wouldn't be knocking into coral heads as I swim.
Some divers use them, some don't. For you to say they're a "joke" is rather closeminded and presumptive.