And come spring comes freezer burn as the water inside the cells expands and explodes the cells. If destroying the brain kills zombies, boom, you just destroyed the brain and hence the zombie.
If all the cells in the body were to burst, wouldn't that liquidate the previously frozen zombie? There'd be nothing but a skeleton covered in goo.
Black text is for sarcasm, also sincerity. You'll just have to read between the lines and infer from context like an animal