> Because web pages and simple web scripting is often done by non-professionals, who cannot be expected to follow standards processes in perpetuity to keep thei

> Because web pages and simple web scripting is often done by non-professionals, who cannot be expected to follow standards processes in perpetuity to keep their pages/scripts working. They often author a few pages and move on with other things in life, which is why browsers being ultra-conservative about breaking stuff is important for the robustness of the Web. I am a professional software engineer at my day job, and we strive to keep our software up to date etc as the world changes. But I am also exactly this non-professional developer in my after-hours. I have written a number of little web apps that solve some small need, and I really have zero interest in maintaining them over time. When I wear that hat, I really appreciate the conservatism of most web stuff.