while silly to check for landing gear down and locked in a c152 For flight training I dont think its silly to be drilled to check if your gear is down.
Most flight students will end up in more complex aircraft, if its already habit to check your landing gear is down when you move to a retractable aircraft you hopefully wont forget it.
I was taught BUMFISH in the C152
first time using it was a mess, after memorising it, the checklist was not an issue landing checks complete in a matter of seconds and you can even time look out between each item. usually started the checklist mid downwind, aiming to complete before turning base. so all that's left to do is fly and communicate