The status quo was already established by a very qualified majority. Changing it should require a qualified majority too.

It's the same reason a thermostat is not constantly switching on and off when you cross the set temperature. Heating will start when you go a couple of degrees below the desired temperature, and it will only stop when you reach a couple of degrees more. Else, you have an unstable system (this is not my opinion, it's very basic control systems theory).