How do so many frivolous lawsuits end up in court, considering there are tons of legitimate ones in line?

Maybe not tons, but aren’t there enough serious lawsuits pending, wherever it is, most of the time? Although the link below is about big business, I’m referring to just in general. If you have a link please feel free to post.

http://www.businessinsurance.org/10-ridiculously-frivolous-lawsuits-against-big-businesses/
Liebeck v. McDonald’s for example.