It was very likely a designers decision. It forces the use the use case they wanted; wireless mice should be used wirelessly. I would bet they fought marketing and management to get this on the final product.
Marketing would want the mouse they can advertise as being useable with and wireless. Female ports are easier to mount and manufacture with they have depth to set the socket. So a plug on the front is much cheaper and easier to manufacture.
The fact the charging cable doesn’t get used in motion means it will last longer and you wouldn’t have people useing fraying cables on the front of their mouse.
Whenever you get a new router or move somewhere, change the WiFi access point name and password. Set it to the same line you used previously. That way all your devices will connect to it without changing anything.
Use a new unique name and password. Never keep the one that is printed on the back of the router. You can make the password easier to share by making it a few words and numbers. Still very strong, but much easier to say aloud to someone.