A salt water fish tank is so much easier than what most people think. If a person genuinly understands the in's and out's of a fresh water aquarium, they will do fine with a salt water fish tank. They are almost identical, fish produce waste, bacteria brakes the waste down, we do water changes to remove the left overs. It really is that simple.
I think one of the big reasons that salt water has such a bad reputation is because there are many lousy freshwater aquarist out there who don't know they are lousy aquarist.
Example; A guy buys a cute little oscar, put's it in his 55 gallon. He feeds it alot, adds water when it evaporates, cleans the tank every once in a while when it looks nasty, basically doesn't do all the things the aquarium and oscar really need. Why should he, the fish is doing fine and is growing real big.
Let's face it, oscars and many, many other fish would survive in a bucket with an air stone and bread crumbs.
Well this same guy now thinks he's a good aquariust. Why shouldn't he? This fish has been alive a long time, grew it up from a baby. Everything has gone great. He sets up a salt water aquarium, treats it the same as he did the oscar and everything is dead in a week or two. He blames his failure (like many others have) on "Saltwater".
It's not saltwaters fault, it's the horrible maintenance and filtering pratice many people have and the un qualified clearks at LFS that offer lousy advise. I guess ultametly, it's the aquarist fault for not educating them selves before getting an aquarium & fish.