It is foolish to assume that just because it does not make financial sense for your "average IT manager" to modify the code, there is no value in "openness". The fundamental flaw of the position is its self-centeredness. Even though there might be no additional value directly to you in your being able to modify the code, there is substantial value in the fact that many others are not so constrained, and contribute. It is those contributions cycle back and add value to, you guessed it, the "average IT manager".