Hey froggy dude -
Maybe because it is tree CARE and not tree CLIMBING.
Maybe because a university bachelor's degree is the equivalent of a highschool diploma 20 yrs ago.
Maybe because a degree shows you are teachable/trainable.
Maybe so you can spell experience?
Shigo has it and so do you, YOU HAVE TO TOUCH TREES TO KNOW TREES. Aka - get experience.
When I started fresh outta the Uni, everyone ragged on me about being golden boy because I made more than the rest of the crew or ragged on me about being big word man because I used "epicormic sprouts" instead of "suckers". Suckers are names for lollipops or "working girls"
It gets your foot in the door when applying. Call and ask if a company is hiring a climber and tell them you are "rilly good" - you get a lot of "No" answers. Not the same when you say, I am a degreed forester, ISA certified arborist and accomplished climber - are you hiring?? You get a lot of "yes" answers.
You learn a lot of academia book minutia about trees and tree biology in university as well as many basic core classes. That is not what means the most to an employer or customer for that matter. A college degree just shows a certain level of sticktuativeness. That you can start something, stick with it for 4 or 5
years and finish it. They have an employee that is more apt to be able to handle responsibility with less potential for turnover or generally flaking out.
It gives you a lot of ethos and credibility when discussing problems with a client. Better than "well you need to do this here cuz its good fer them thar trees"
If you don't get a degree, you need to get a certification of some kind to differentiate yourself. Explaining how good you are at climbing and rigging means little to most clients and you will certainly lose their interest in explaining the minutia of what makes a "good" climber/pruner/rigger.
If nothing else, you go to college for 4 years so you can answer questions like this on your own without relying on a message board.