There is probably not a huge reason, but I know that since the current passes through the esc, they might put female connections on the esc so that the wires don’t touch and short out or something. If that isn’t it, then they probably just wanted some standard for esc and motor connection. Also, about putting the female connector on the thing that passes current, batteries have female connectors so that the battery connector doesn’t touch something conductive and short out.
All right. Tips that can be a life saver. The first is to know that brushless motors are waterproof. One time I got some loctite on a motor and I only rinsed off the loctite because I knew that the motor was waterproof, so keep that in mind. Most things are probably waterproof though, as long as you dry them completely before trying to use them again. Another thing is that on some planes (like the ft mini mustang) the servos that are glued inside the tail can come off because the paper peels away from the foam. A lot of people don’t do this, but for planes where the servo is glued straight onto a flat piece of foam, I put a zip tie around the servo to hold it onto the fuselage for extra safety. Again, you don’t have to do the last one, it’s just if you have the same issue.
Yeah, my tips aren’t exactly life savers, but they were helpful for me, so I hope that they can help you (actually I hope that you never need to use them).