That deters honest complaints from poor plaintiffs. The Economist may approve, but justice shouldn't depend on the relative finances and/or power and status of the opposing parties.
Of course it does, often. But that's a pathology, not a feature to be proud of.
It's true that some complaints are irrational, vindictive, or vexatious, but the system seems quite good at identifying those already.
> That deters honest complaints from poor plaintiffs.
If the complaint has a high probability of success then it has a low probability of making the plaintiff pay costs. If it has a low probability of success then isn't that what we're trying to deter?