I'm all for it. If you bring suit the other party should be allowed to cause you to have to continue if you feel like dropping it. There is some potential for abuse there though, this is not a simple matter.
Counterpoint: if you want to sue everyone in the Unites States for pirating your porn, ask for $50 in settlement for dropping charges, and drop charges for anyone who shows up in court with legal representation, should the judge be sympathetic to you? Isn't a frivolous lawsuit a frivolous lawsuit anymore?
In addition to the counterpoint that newjersey brings up, we could also restrict this power to cases where the plaintiff is the government (local, state, or federal).
While nuisance suits from private actors can totally be ruinous, the potential for harm from government actors is so much greater.