you generally don't say "i don't understand why..." for things that are obviously understandable. you usually use it for things that are inexplicably broken in

you generally don't say "i don't understand why..." for things that are obviously understandable. you usually use it for things that are inexplicably broken in some way. "i don't understand why they can't move these things 2 inches to the left" "i don't understand why the entrance to this parking garage is blocked by trash cans every tuesday" "i don't understand why they can't make this app remember your login" "i don't understand why you can't change the temperature on this thermostat" "i don't understand why anyone likes bacon" hmm.. which of these is not like the others?