I agree with what's been said here, for the most part. If the conditions are questionable, it's really the jumper's choice to get on the plane. In this case there were some clouds already, so it wasn't totally out of nowhere, although things did close up quite fast. That's largely irrelevant though, the DZ did their part in providing a ride up, which is what you pay for.
That being said, it bothers me a lot that they're willing to send tandems into a sea of clouds with no ground visible whatsoever (to make matters worse, we sighted airplane traffic under the clouds on the way up!). It says something about their priorities and concerns for regulations when nobody else involved (tandem instructors, pilot, DZO, etc) has a problem with that. But hey, it's not my license or life at risk, I guess. The whole situation just left a bad taste in my mouth...