Our management doesn't understand open source. I'm not sure that our boss understands that we are using OSS for development.
In the last time, our boss wanted to release some stuff as open source, but the package should be bundled with a support-contract, so I don't believe he really knows what Open-Source means.
So in one sentence: we don't give back to open source because our management doesn't understand the concept behind open source.
Update: Now we have an OS-product, but our management do not understand it until today. Actually we did it, because some of our customers talked about open-source (and really meant for free).
