What is wrong with people handling garden hoses?

I found myself having to replace the hose coupling several times a month. I
have an exterior spout and I connected a garden hose to it. So every once
in a while I had someone come by to either do pest control, or repair stuff,
or pressure wash something, or maintain the pool etc...they need to use
water. Pretty much every time they will end up breaking my hose coupling.
Either the strip the threads or cause it to leak. I think they don't turn
and unscrew the coupling from the spout, they just try to yank it off with
brute force. So I have to cut the hose and put in a new coupling.
Sometimes they even use my garden hose and have to attach their own fitting
on the other end and that usually result in breaking the couplings on both
ends.

I don't understand why they kept breaking it.

Now this time I had someone pressure washed a driveway. After he is done I
know the hose coupler has to be replaced, cause when I turn the water on it
shoots out to the side again in all directions, it's practically impossible
to turn the water on or off without getting soaked.

Except this time the problem was not the plastic coupler on the hose, I
replaced that already and it is still leaking. Here is an image:

http://img.villagephotos.com/p/2005-...6/P1000492.JPG

I have indicated in blue lines where the water is jetting out when I turn on
the spigot. It is not the black coupler attached to the hose. It is the
metal coupler above it. However I tried removing it with a plier, no luck.
It is locked tight. I tried for 2 hours and ended up stripping the metal.
This is the part I need to replace but this part has been there since day 1,
so it's been there like at least 15 years. It's not coming off. I tried
WD40 no luck.

Any other suggestions?

MC