People don't look after their tyres anyway. I see people almost daily driving around with a badly under-inflated tyre, which is wrecking the sidewalls, and risking a catastrophic failure. They don't care though! The number of times I've pointed it out to people and they are like 'so what'.
Having had a blowout on the outside lane of a motorway on a front tyre, it was all I could do to keep control of the car. this was a two week old, premium brand tyre by the way with a manufacturing defect.
People also don't realise that tyre rubber hardens with age, resulting in sidewalls starting to crack, and treads losing substantial grip. The industry recommends I think six years as being the maximum safe lifetime of a tyre. If you don't swap your rears to the front, you may only wear the rears down by half in six years, but then are driving around with compromised tyres... you would be increasing risk by transferring those to the front!