The GPL and LGPL are needlessly difficult for mere mortals to understand in their entirety, and as you've alluded to, many lawyers would interpret it differently. I suspect many different judges would too.
I think the evidence is rather to the contrary. Most lawsuits involving the GPL are settled out of court, precisely because the lawyers for the violating party tend to realise they have no leg to stand on. Of those few cases which have made it to court, the judge has always decided in favour of the GPL. That is, the GPL is as solid a guarantee of code freedom as you could wish for. The lesson, from the point of view of an entity that wants to distribute non-free code but making use of some free code, is simply to play nicely with the community whose work you are using gratis. Keeping to the original authors' intent is ultimately cheaper than either writing your own replacement code, or paying lawyers to fight it out. In addition, if you want legal certainty , most GPL authors would probably be happy to assign you a separate non-exclusive commercial license, in return for a small payment or royalty agreement. Regards, Malcolm