As a cheaper, cleaner hydro setup. I didn't want dirt in the house and all the potential bugs that entails, and I wanted more direct nutrient control. I was originally going with a coco/perlite combo, but then came across a few 100% coco guides and went with that instead. My results are going to be shit, but I'll stick with it.
I really don't care about yield though (only my pride does). I'd be fine with a dry ounce total. Next time I'll have perlite, and accurate pH readings from the beginning.