My pet theory: I'm pretty sure this is because when HTML5 became a thing, some major tech blog showed us what an HTML5 page would look like (simplified doctype, meta charset) and they included the viewport settings that disabled zoom.
Then pretty much everyone copied from these guides, and here we are. I remember I had used HTML5 skeleton templates for a while before I learned that the "maximum-scale=1, user-scalable=no" they came with is not a good idea.
Then pretty much everyone copied from these guides, and here we are. I remember I had used HTML5 skeleton templates for a while before I learned that the "maximum-scale=1, user-scalable=no" they came with is not a good idea.