Marty, you forget that many people who are running into issues with their SCA homes are likely to be people who were not the original owners. So many homes here have been sold over the years since we had the plumbing issues here and although a seller is supposed to report issues f this kind, I’m sure many do not.
We also have to problem of many original owners who knew nothing about what the repairs were to be as far as material used. We can’t all be mechanically savvy… Personally I had no clue and had to ask a friend who was a retired engineer to check what was being done to my home for me.