That's a value judgement. As a hacker you can't do everything.
Prey is a polished product that you can trust to work. If you are into this sort of thing, certainly you can achieve more functionality and better security by rolling your own, but I don't consider it a prerequisite to hackerdom anymore than soldering your own motherboards. How often do you expect your laptop to be stolen anyway?
I'm sorry but that claim has no credibility with me. Setting up the proper cron jobs, server-side components, and verifying that everything is working under a variety of circumstances will take much more than the 5 mins it takes to install Prey.
Just because you've already done it and you have a pre-rolled solution doesn't mean you didn't invest that time, and don't fool yourself.
You only need to set up a cron job to create a reverse SSH tunnel into your home server. That way from your home server you could SSH into the machine, no matter where it is.
Prey is a polished product that you can trust to work. If you are into this sort of thing, certainly you can achieve more functionality and better security by rolling your own, but I don't consider it a prerequisite to hackerdom anymore than soldering your own motherboards. How often do you expect your laptop to be stolen anyway?