Surely it's better to at least make sure a car is safe once a year rather than not at all.
We all know people that don't look at their car mechanically for months on end,and if the MOT system wasn't in place then they wouldn't get looked at all until something either fell off or broke.
I can hear what your saying about people expecting too much from an MOT,but a lot of that is caused by peoples ignorance on just what the MOT standards are and what is covered on and tested as part of the test.There are so many myths about the MOT test that it's job for anyone outside of the trade to understand what is the truth and what is make believe.
At least by buying a car with 12 months MOT you know it 'should' be safe and if anything does happen you have some sort of come back on the garage that carries out the MOT.
I can honestly say that if the test goes from being annual to being one every 2 years and the time that a car is tested from when it's new goes to 5 years rather than 3 we could end up with mayhem on the roads.I'm not just saying that because I'd loose a lot of work(and probably my job),I'm saying that because some of the things I get to see as part of my job would really scare you.
Just one example is the amount of people driving around in cars with tyres with the canvas or wires showing through them and the owner thinking it's funny or making the age old joke 'I got my moneys worth from them'.Then you look at the back seat of their car and theres one or more child seat in it..........