Every big corporation keeps a certain amount of legal staff on hand at all times. Showing up to court just to have a case thrown out presents little to no burden on them whatsoever. A case that doesn't make it to trial is far from any sort of "legal battle." They don't need to be protected from these lawsuits that will obviously be thrown out, at the expense of access to the court system.

You're right: the court system should not be filled up with pointless get rich quick scams and that is why judges are given the ability to choose which cases go to trial.