I had the same discussion while camping listening to stories on how a friend is on their 3rd pool guy and the pool is still green. I told them how easy it is and that I spend about as much in a year as they do in a couple months of bad service.
As I am sure you are aware this site is nonprofit and is supported by Us the community, if you are able I hope you will consider becoming a supporter, so we all can continue to help each other and people who "get it" with luck and some gentle persistence perhaps you can get your friends to give it a try too, for their kids if nothing else.