Webmaster is a very broad term. Remember not every site is run by a single person, in fact most of the big ones have teams of many many people working on them. Depending on their systems map, their software architecture, their browser compatibility requirements and a whole host of other concerns using an SSL cert is not always just a matter of dropping the certificate into apache. It could take months to properly implement without breaking the system and upsetting users, and those months come with costs, developers on the coasts cost a business more that $100/hr (cost assumes all costs associate with a developer not just what you are paying them), so assuming 500 developer hours your already in it for $50,000 and that doesn't include planning and testing. Additional servers could easily run you another $50,000 including the labor to set them up. By the time all is said and done, adding that little s to the end of your http can easily cost a business a quarter of a million dollars. That is why everyone doesn't just use it.