There are several reasons why people don't wear Safety harnesses, but even more reasons why they don't climb safe.
I think the biggest reason is because the TMA (Treestand Manufacturers Association) does not promote it as well as they should. Therefore, bowhunters are not as educated about treestand hunting danger as they ought to be. Notice I said the word 'dangers'.
For the TMA this would be a double edged sword. If in fact they warned hunters about the dangers of climbing into treestands, and started talking about all the carnage that goes on, then too many folks may get scared, would stop climbing, and their sales would go down.
There are really an enormous number of falls all across the country every year. Most are not reported to state DNR offices. Hospitals call hunters that fall "Deer Divers" because there are so many. There are fatalities, paralysis causing quadraplegic or paraplegic cases, losses of limbs, shattered backs, legs arms and many life changing injuries that we just never hear about. Now why would the TMA ever want to talk about this.
Frankly, I blame them for this carnage. I know the old story, you lead a horse to water..., but I don't think the horses have been led to the water yet.
I do know one thing for sure though.
I will never hit the ground again.
Been there, done that.