Agreed, that seems to be the general consensus about Farasan as well. I think much has to do do with people's preconceptions, but also the time of year and depth. each to their own!
Saudi has quite stunning diving. I have dived Jeddah, Al Wajh, Shu'aibah, Qadhima and spend as much of my time as possible in Yenbu - heading to a mountain of an island off Um Lujj tomorrow. Never dived there before but the fishing is apparently excellent, hopefully a good sign.
Most (90%) of the diving I do is off shore and again the majority of the time our boat is the only one around. There is talk of the country seriously opening up for dive touirism next year and there are already some charters operating to the Farasan using liveaboards. I would seriously recommend diving here before it gets as over-crowded as Egypt.
Jeddah has some good sights Ms Mary, Ann Ann, Champagne, Swiss AIr and Aquarium but most of the rest of the popular sights suffer from over fishing and pollution (sewage, construction and cement factories).