Not the vast majority, but a significant minority. The term vast majority would apply to cyclists. Turn signal usage appears to be about 25-30%

In the last two days I've seen kids driving golf carts and actually driving safer and being more courteous than the adults.

If they are younger than the required age to drive I’d like to see the license of the person who gives them permission to drive, revoked. They endanger the kids and everyone else on the road. There is a reason for age limits and they blatantly break the law.

This is not true as a blanket statement. Normally the vehicle is insured. You may have exclusions on your policy to reduce the cost of the insurance. In our case, the cart is insured no matter who the driver is. For a myriad of reasons we wanted it this way.

A cart is a dangerous weapon.. same as a car. (which has an age minimum 16 and needs a license. Cart should be the same restrictions, and insured. Both can kill.

This thread the OP wrote: "kids driving carts recklessly in TV now.", not about adults driving recklessly.
One can tell by some responses who let their brats drive their golf cart while pointing fingers at the adults who actually pay to live and drive their carts here.

We solved that problem before it even comes up. We (hubs and me) are the only authorized drivers.