I had attended a talk by Vint Cerf at Stanford where he had posited that the reason the web took off was because people could see the HTML source of websites an

I had attended a talk by Vint Cerf at Stanford where he had posited that the reason the web took off was because people could see the HTML source of websites and start writing their own HTML.This, he believed, led to the exponential growth of web content. So, I guess then, "view source" was quite common.