"the nutters are the rule rather than the exception"
I've only got a sample size of 3 Arabians I've known well. Lilly liked to be told 'please & thank you', but she was gentle, sane and very patient. Trooper is 3/4 Arabian. His Appy sire was used on the roughest cattle because he was a very aggressive stallion who loved a fight and who didn't mind biting his rider if he got a chance. It took years for the sire to accept humans as a plus. But Trooper's personality came from his purebred Arabian dam. He takes care of my youngest daughter. As an ex-ranch horse, it probably isn't surprising that he is level headed on the trails.
Mia is the stereotypical "Arabian mare". She was very nervous, very intense and spooked a lot. After a lot of work, as in a couple of years of work, she is starting to calm down. There are even signs of a slightly lethargic, lazy mare starting to peep out. She may or may not have had some nervous tendencies from breeding, but I'm increasingly convinced it was 'trained' in to her by owners who didn't ride her and who left her to live in a corral.
Mia needed exercise. She needed to get out of the corral. She needed to move & see things. It is like when I tried to adopt a Border Collie. The woman who did our home inspection told me the dog I was interested in was too crazy for me to handle. She also admitted she kept him in a crate 23.5 hours a day because he was nuts. I told her I'd be nuts too, if someone kept me in a crate for 23.5 hours a day! I failed the home inspection...had a bad attitude and wouldn't mesh well with Border Collies. But don't tell the Border Collie I own right now. He thinks I'm great.
If Mia had been ponied out at 3 and ridden out at 4, I think she would have been uncommonly sane at 6. Getting a total newbie owner at 7 and not being properly broken until 10 did Mia no favors. I think a horse bred for endurance needs a level-headed rider to exercise him and introduce him to the world in steps he can handle until he becomes confident.
I don't think Arabians are nuts. I do think they need more exercise, and of the right type, than many other horses. Having nearly ruined Mia at one point, I think many Arabians need a horseman, but too often get just a rider. And I think Arabians need trail work.
All IMHO, with an admitted small sample size.