Too many people are in La La land, thinking the company they are employed with owes them living. This couldn't be any further from the truth. Successful companies didn't become successful by hiring people to play games and take naps. Those companies hiring people to do just that are out of business or have one foot in bankruptcy. Successful companies became successful by hiring people who work.
Work is an OK thing.
Once you have completed work, you feel successful, and deserve to be compensated. I wouldn't argue the fact that an on site gym would help in keeping employees fit, healthy, and there minds clear and creative. I think a gym would be a great perk. It just shouldn't take the place of good, old-fashioned work. Research the salary for the position you are wanting and compare it to your own experiences.