Yes, maybe it was not clear but that was what I wanted to say: It should be the job of the website to decide the expiration date for it's certificate. So they d

Yes, maybe it was not clear but that was what I wanted to say: It should be the job of the website to decide the expiration date for it's certificate. So they decide if they want to look shady, careless and use 10 years certs or look like trustable and serious and use 6 months. And indeed users would be able to use that to determine the trust they give to a website. So in the end, websites determine their 'trust value' without the browsers 'police', that will let the possibility for special cases. For example, if I do a device that is to be used out of internet for 3 years, logically the user will not see an issue with a 5 years certificate.