This should be the top comment. Users (including technical users) all behave weirdly by writing "www." depending on their mood or previous experiences. Developers setting up webpages do the same and often manage to screw up a CNAME on the www subdomain or to have two valid certificates for the www. And the non-www. Also, once you rotate cert you now have two to rotate. It's a mess and chrome's change is aiming at normalizing this. The complaints make zero sense.