it’s frustrating that so many people have a fear of snakes...but does that have to be taken into consideration because the number is so high? Looking at it from let’s say United Airlines prospective things get a little tough. if they allow snakes...someone will be seated next to a passenger that has one. if that passenger express discomfort they have to find someone willing to switch seats before the plane can take off (they have to do the same with dogs). When the flight attendant ask if anyone would be willing to sit next to the passenger with the snake less people will be inclined to make the switch and passengers that have a deathly fear of snakes will hear the announcement and could possibly go into freak out mode (again this would delay take off which would have a negative effect on their customer service.
its not fair. and a big part of me wants people to be exposed to snakes because well...they are great for all the reasons you listed and way more. but its hard for commercial business to take that stance.