The biggest issue with local breakout is that every port that has an AP on it, has to be configured as a trunk and managed as such. With traffic tunneled, the only place you have to configure that trunk is between the controller and the layer 3 switch that it is connected to. You then plug in all of your APS, and they come up almost instantly, which means that your deployment and maintenence for traffic tunneled back would not require a network engineer to set a trunk before you deploy or replace an AP..
Controller hardware is less expensive historically that you can put a second controller in the datacenter next to the first one and that will provide redundancy for the first. Centralized licensing means that you would only pay for the physical hardware and not licenses for the second device.
Many statistics like AppRF, Voice Tracking, etc require that the traffic be tunneled back to a controller, anyways.