Maybe some of these "roofers" are not really Roofers, but imposters.

I had an old woman call me and ask to inspect her attic, because two men knocked on her door, said that they were fixing a flat tire in front of her house when they heard a sound like CREAK-----SHUDDER and they saw the whole upstairs twist.
and she was in luck because they happen to have seen this before, and they knew how to brace it from getting worse, and the 2 choices were regular lumber at $8,000, or $10,000 for pressure treated lumber.