It's not terribly hard to unlock and root a Nexus device, but mucking around with ADB simply isn't for everyone. If you want a somewhat more automated rooting experience for your 2013 Nexus 7, there's the Root Toolkit from Mskip. It's available now for all your modding needs.
Mskip is a senior moderator and recognized developer at XDA. He makes it his business to build simple root toolkits for a ton of devices.