Ignoring for a moment the moral issue, if such phenomenon causes a (relatively) large amount of money to flow from (software) companies to "patent trolling" ones, isn't it still positive for the economy?
NPEs don't grow the economy, and by their activity they hinder or kill companies which do.
So no.
Why? Where's the benefit for the economy? If somehow the patent trolls reinject the benefits they make (ie what they obtain from the law suit minus the lawyers/legal fees) in the economy, perhaps we could say it's maybe a positive outcome, but there are no garantee that the infringing company would not have done so. So where is the benefit for the economy?