This is a dumb and outrageously anti-democratic idea, and is a much worse cure than the disease it's attempting to fix. If 65% of the population supports a law it's favored by 30 points-- far higher than the margin of most elections-- and yet would not exist under this system.
There's nothing magical about 50%. The bar for "this policy should be inflicted on everyone" should be very high--I'd argue much higher than 50%. At the same time, the bar for "we should stop inflicting this policy on everyone" should be extremely low. I'd argue a 1/3 minority should be enough to repeal a law. If one out of three people feel they are harmed by something, maybe the government shouldn't be doing it.