Why does my 2012 Nexus 7 get so bogged down during app updates?

Every time there is an app update, my Nexus 7 becomes amidst completely unusable. The system grinds to a halt, the apps themselves take forever to load (I'm talking 20 seconds just to open, let alone start to actually load), and web browsing is basically stopped. I'm on version 4.3, and rooted. I've never had this problem in previous versions of Android.