I mis-cast once onto another angler's line and got yelled at, threatened, and invited to fight.
Some guys can can be dicks that's just the way it is.
Around this time I realized that the other 6 people fishing the run had 12' of line below their floats and were ripping on the rod at the end of every drift. Flossing! And one of them was flossing with roe! Most of them caught big springs within an hour but no fish were biting my presentations so I moved on to other runs in the area.
Just because these guys had 12' of line below their float doesn't necessarily mean they were flossing. 12' of line below your float is appropriate in 13' of water. You want your presentation in the fishes face which is on the bottom of the river. Now if they had 12' of
leader hanging from their weight, a la Fraser BBing style, then you could accuse them of flossing. It sounds to me you are still new and can't tell the difference between legit angling methods and snagging especially when someone said to you...
One guy approached me and told me that my float depth was too short and I needed the weight to drag through the school of fish to catch anything
He is correct. You need to put your gear where the fish are. The difference between flossing and appropriate angling is leader length. The proper leader length is about 1.5' - 2'. This will minimize the accidental hookups when you put your gear where the fish are holding.
people float fishing with 12 feet below the float (in 8 foot water)
Anybody fishing 12' below the float in 8' of water is going to catch nothing and most likely lose a lot of gear. There are lots of inexperienced anglers to be had in the fall salmon season on the Vedder.
So after a 13 hour day of fishing and driving, applying all the things I've been learning and studying for the last month, I got 1 hookup and saw 3 fish legitimately caught, and about 50 other fish flossed.
Your descriptions of the techniques used for the waters you fished are too imprecise (water depth? vs. float to weight length) to make any claims of flossing. I'm not saying it doesn't happen, obviously it does, but I think you need a little more experience before you start making accusations at people that might just be properly fishing the water they are at.