Respect - it goes both ways.
as a club events director, it's very frustrating to hear people feel alienated from joining a league. its kinda like when i was 7 and afraid of roller coasters, and all my friends would go ride without me while i sat with my grandma feeding pigeons cold french fries. Then one day i got the courage to ride one and i had the most fun i ever had and became addicted to riding roller coasters.
I like this analogy and it's right in the sense there is a plunge to be taken at some point if one wishes to participate, but I can see both sides. I've never been in a league myself, but I play often enough to have met many players who do. Awesome guys, really. Disc heads who have game and a lot of great stories, they take their time, make their shots and have etiquette ingrained. If they fail, they fail to recognize it's public and etiquette is learned. If they are unfriendly, its because they are too focused to step back and give the type of players that annoy them a fair shake.
The type of player that will annoy the focused golfer most is the one who is just there to huck plastic as an excuse to drink and chill. They come on with a case of beer, shirts off and a fresh tye dye speed 13 driver each and you KNOW you are going to be picking up their cans while putting up with every etiquette violation you can name.
And finally, in varying degrees there is the middle class disc golfer. Depending on your scope, it is more than its share of the middle third of golfers. Often, they respect the course, but not so much their game and thus probably play the most holes with their time than any other level of golfer. They would rather maintain a good pace, maximizing their limited available disc golf time, often taking a couple drives to test things all the while dodging both extremes of players on the way.
My advice to all is simply - respect. Be cognizant of all parties and their level of enjoyment. While there is a right way to keep disc golf on public land, there isn't a universal way to relax and enjoy. If a single wants to play through on league, let him, he's not going to take long. Otoh, if you're a single and know your courses well enough, avoid league night and be sure to understand that's how the guys at that stage of their game enjoy to play it. It's also their right to play with stools and flip through 16 discs for the right one because the wind just picked up. You would respect granny walking through it with her dog, it's her right too so extend that to people who play different. Mi Casa, Tu Casa. Only the city owns that shizz.