Because my only other choice is an area surrounded by roads with a lot of children playing. While my dog isn't a problem with children, parents get worried when they see 40 kgs of dog running towards their loved ones. Furthermore, I would need to travel 20 miles to avoid farmers fields. I stress again that there is no cruelty is using an electric dog collar in the correct way. The damage is done by people mis-using them. I am sure, though cannot substantiate the fact, that more dogs have been hurt by owners beating them for peeing on the carpet etc.
What in your mind is better, a dog that has the freedom to run and be stopped before being shot on crushed or one that gets 'walked' on a lead at its owners pace?
Unless I am running in an unknown area or farmers fields I no longer need the collar. My dog has a better life than one whose exercise is on the end of a lead.