There are some setups that benefit from having food in the water column almost consistently, the obvious example is a non-photosynthetic coral tank, as they are the cleaners. However there's nothing to say you have to dose food constantly, many fish are consistent grazers/hunters (lots of anthias fish come to mind) so throwing food in the tank 4+ times a day can be useful, not to mention corals do like food too, they don't just need light to live. But a draw back of something like this is you need to go a bit further to keep the water clean than the average reefer.