Contribution always is connected to development costs.
If the developer is interested in result, the price is his skill and time.
If the developer is not interested in result, he should charge money.
Please show me even one consumer who will resist to pay for opensource contribution?
The difference is that opensource solution will profit from cross development, reducing amount of "bicycle inventions", patent suits and wars, increase security by more pass-thru's --- pretty much all advantages of opensource model.
But the scheme to mis-use (expoit) developer time was never part of RMS idea.
If one is to make money off the development time of others, he should be legally obligated to compensate it to them.
I never thought KDE and Qt are this stupid.... :(
Maybe its a very good idea to start a toolkit similar to Qt from scratch.
Maybe RMS releases GPLv5 where he addresses this case.