This was my thought too. It’s not like the computer is super heavy and large. It’s also meant to sit on your desk. This seems like a perfectly fine design decision.
The charger on the bottom of the mouse is incredibly stupid. You can’t use it while charging.
It's still silly that they did not just put the button on the back like their previous mac minis. Also, someone using an non-apple keyboard might be using the button more often, which seems plausible given that the keyboard is a separate purchase starting at $99.