Leaks, so what

I have had a few people call and express their opinions that leaks from plumbing vents are not that important. After all, they say, whats a few drops of water during a storm. OK, lets say its not dripping on your insulation or your ceiling, but simply wetting your roof decking or rafters. No big deal short term. But roofs last 15-20 years, and plywood decking and cheap 2x4s arent designed to take continuous wetting. Over time, the plywood decking will rot, the 2x4s will rot, and you end up with a real expensive repair when you replace your roof. When you consider a CQ installation is less then 200 bucks generally, it makes sense to take care of the problem.