Carey, I agree with you that there are LOTs of different opinions. Lots of "experts" do things that sound crazy. But, here are two caveats to that on the dilemma of QT.
Maybe they see no need to Qt. Maybe THEY have never had an outbreak like this, because they've been super lucky. It doesn't happen to everyone. Or Maybe they have a supplier that QT's for them. We have an LFS
near us that does. Maybe they keep their tank at a lower SG
and disease isn't able to get a foothold. So many variables and the thing to remember is... In the end this isn't their tank. Their experiences are going to be completely different than yours. That doesn't make anyone wrong.
Second... There is no doubt about the role that experience plays in this hobby. A lot of these "experts" will tell you that they can get away with things that inexperienced people shouldn't even try. They know the fish and the coral and and pick out superior specimens. They know exactly what they can get away with and can't and can push boundaries that could make newer tanks fail. They can recognize signs, that new folks miss, much faster and avoid the complete disasters.
When we decided to get out tank, my husband and I started picking up every bit of knowledge we could. We window shopped for years and read text by every conceivable expert. Two of my absolute favorites are Anthony Calfo and Bob Fenner. We cruised lots of forums and read lots of information. We took every bit of advice and then formulated an opinion on it. And then we decided what WE thought made sense. And that's the big magic moment.
YOU need to take in all the information and pick out the pieces that work for you, that make the BEST sense to you. That is what every one of the "experts" did and that's how they became "experts". They came up with a system that works in their tanks, in their special situations and have made it work for years.
This "difference in opinions" is found on every facet of reef keeping. What food is best, what light is best, whether or not to QT... Blah blah blah. On each side there are countless success stories and it boils down to this. There is more than one way to skin a cat... Err fish.. Ah never mind you get my drift. There is no right or wrong answer. Folks do what works for them. And if it works for them... That is wonderful! But it doesn't take very long to look around and see someone say "that doesn't work and this is what it did to my tank". Follow your gut and decide what make sense to YOU. You went with no QT, added fish and got seriously burnt. QT now makes good sense to you. For whatever reason you do not appear to have the puzzle pieces needed to run your tank without QT. And that is what it is. Not right, not wrong. Just tried and true experience in YOUR tanks. Welcome to the road to "expertise"