I still believe that skimmers are a boon to the system and equally as important as water changes. Nature uses wind and waves to skim the oceans and reefs...if it's good enough for Mother Nature...who am I to Argue? I think that some people try to convince themselves they don't need to use them do it because they can't or don't want to spend the money that is needed for a good skimmer. I know I am probably stepping on toes here but I feel that one should use every means at ur disposal to upkeep the tank. I use as many as I can. Skimmer, macro algaes, sump, water changes, ect. Even with all this I plan on adding a canister filter and a 40 gal. refugium. It's like water...some people actually use tapwater but RO/DI is better. A skimmer may not be ultimately "Necessary" but neither is a sump or a water purifier.
They all contribute to a better, healthier tank. As far as Eric Boreman and his book is concerned, I got it about a month ago and have been reading it some as I have the chance. i will make sure to see what his take is on skimmers, to be sure. But even if he had been running a system for 10 yrs without...he is Boreman and I am me. He is a leading authority on corals and I am not...He is probably good enuf to know how to eco-balance his system on a whim. I'll take a good skimmer to help couterbalance for my lack of skill in that area. Again- Even with water changes, I have seen the gunk that my Euroreef pulls out and I know my fish and corals benefit from it. Necesary for you? Maybe not...For me? Without question. Just my humble if not long winded opinion