Many of the “frivolous” lawsuits you’ve actually heard about are effectively smear campaigns against the plaintiffs.
The lawsuit against MacDonald’s for the hot coffee one is a great example.
Yes, people do dumb stuff, or fantasize that a situation could be their golden ticket, but that is the cost of having a civil judicial system. You either have to allow some crazy in, or prejudge and filter out what you’d consider legitimate cases. I just don’t have the energy, or care enough to be annoyed by inefficiency in the a system that I rarely interact with.
The criminal system is a different story, because the way we currently prosecute different kinds of crimes offends my basic sense of fairness.