I can think of plenty of reasons
1. It is more prone to being knocked out of alignment by kids, lawnmowers, or animals
2. The cable is more prone to damage from lawn mowers, weed wackers, and animals chewing it
3. It is harder to find line of site because it is lower to the ground
4. If the tech doesn't install it right it will cause you more headaches than it is worth
But ya if it's an only option try and get the pole as close to the house as possible and inside a flowerbed or yard feature. Not in high traffic areas and especially not in your horse pen!!!
If the customer has a deck I would use it
