Earlier quoted context omitted.
You're assuming you have access to cron on the machine that code is running. Lots and lots of websites are running on shared hosting, where there's no such thing as cron access.
This is the perfect example of something that could be run on an always-connected, dual-core Atom machine (~$200) sitting in one's office. I don't understand the insistence on using a paid monthly service for something so simple. My crappy consumer router at home runs cron jobs.
If there was a place to learn everything there is to know about hosting a site yourself, then that would help. Even better if it was easily accessible, trustworthy, and simple to understand. And more so if it displayed proof that you only need minutes to diagnose and fix the most common problems.