So you are essentially saying this guy should do it for free. "Will the person be deprived of their normal source of income for exactly the time period require

So you are essentially saying this guy should do it for free. "Will the person be deprived of their normal source of income for exactly the time period required to do the work?" Does it matter? It will most likely be on his free time, which for me is many times more valuable than my normal income. This is why developing open source is going down a dangerous path: When you work for free once, people expect you to work for free always.