I've seen a lot of really stupid gym behavior in my time as a gym member and as a gym employee. I only spend 4 hours working and probably only 4 more on my own time at the gym per week but boy am I well aware that people stupid.
One case on Sunday, which fiance told me I was overreacting to, was a girl who was not only working out in really stupid ways but also wearing a horribly offensive t-shirt. Her t-shirt espoused hate for both gay people and women who have their period. Perhaps I didn't need to get as rowdy about this as I did but she was also squatting with the worst form I have ever seen from a woman who looked fit. She also did sit-ups on a stability ball that involved violently throwing her upper body up. I had to resist telling her she wasn't using her abs and instead just hurting her spine.
She is not alone. There are a lot of stupid things you can do at the gym. I particularly like numbers 4 and 6. The explanations for these two are the root of my gym annoyance. Unnatural movements at the gym do nothing for you. Number 1 isn't bad either. I mean, at what point in life do you need to move in that way? Except for taking your lazy legs off the coffee table the answer is never. The abductor and adductor machine look fun but unless you're a working girl, I really doubt this is necessary for your life. Squatting and deadlifting are good because they imitate things you actually do.
I'm going to stop ranting now before steam starts coming out of my ears.