It is extremely simple and quick to install a BSD or Linux operating system with Apache and to start serving webpages. You can usually just boot from an installer CD, follow a few prompts and have a working system in less than an hour. And if your website is already designed and your domain name already points to your IP, a few minutes later your website can be up and running.
Because it is so easy to get started, people with no Unix or other relevant experience can moonlight as ISPs or host their own websites.
And since Apache and most Linux and BSD operating systems are so stable, you could probably just forget about the server and it'll still be running great a year later. (In fact, I have had past jobs where I know the actively-used servers are no longer maintained and continue to run great -- including one Debian Linux box with an uptime of 485 days and counting.) Of course, this is not a good idea and I'd never suggest that an administrator entirely ignore their servers.
News: Host Security
