I suppose you need a lot of insurance to protect yourself and your family.
But I've never known anyone who sued their plumber. That's not to say it can't and doesn't happen. But it must be somewhat rare. Heck, the developer who built my condo never brought some items up to code. He told me flat out that the city will either make him change things or not, but he's not doing it because I'm mentioning the code. We had tons of problems and we never sued. Our condo president was a lawyer for the City of Chicago. You know what he said? Lawsuits were costly, risky crapshoots. Lots of people wanted to sue this developer, but we consistently realized it wasn't worth it. I still made out great on the condo.
Our teacher's union has over a million dollars in insurance to cover anything that happens in a classroom when kids are in your charge.
I'm usually glad I have the insurance I do, but I occassionally think that it's a bit paranoid.