The MAC address is very important for developers. It tells them which GUI elements are accesed, what error messages are common and what features of the program are accessed.
There's an honest, non sneaky way of gathering usage information: pay for rigorous testing and price the cost into the product. Telemetry is lazy, invasive, and user hostile by default. Every bit of information acquired from users should be given with informed consent or not collected at all.
It's hard to really stand up to that kind of situation.