Except all the machines have the same feature set I mentioned.

Agree that wanting to hire cheap developers is why they did it that way, the current interface is so laggy that I would bet it is Web based, on top of running Android for nothing.

That's not a problem of the platform, but is a problem of the developers.

The extra cost of an Android capable tablet (maybe $200 especially wholesale) is a minimal hardware cost considering the overall price of the equipment is in the thousands.

But finding good embedded developers is a very difficult problem to solve, much easier to find Android app developers and then you get the Android eco-system for free like device management, OTA updates etc.

Put all the sensors and controls on a USB bus and you need one or two actual embedded developers to deal with the drivers and the rest of the developers can build the UI that people see.

In the case of a gym, the person buying the equipment is the customer, not you.

They want features that will make you "sticky" to the gym, plus save costs on training you on how to use the equipment.