I guess , it’s not the trainers fault, we’re all prone to short cuts. In a gym you can bounce your client from one machine to the next with little thought until the 60 minutes are up, next?! No one wants to feel like they are on a covey-about especially not when they are paying a premium for it, although granted, somewhat cheaper in gyms.
I quit my job in a gym because it was so dull, I needed to break free from the walls, the confines, the restrictions and do things my way. If I had stayed, I know I would not have felt challenged, and when that happens we get dissatisfied with our jobs, lose motivation and so on. Our performance drops making our service worse and intrinsic motivation becomes non existent.
You’re not valuable in a gym because anyone with a Level 3 personal trainer qualification can do what you do and the gym doesn’t care who does it. Make yourself a valuable resource, refine your skills and start working for yourself.