It would prevent vendor lock-in. Some time ago, before government officials become more aware of IT matters, it was common practice in government contracts in P

It would prevent vendor lock-in. Some time ago, before government officials become more aware of IT matters, it was common practice in government contracts in Poland that consulting company creating website or bespoke IT system would keep code copyrights for themselves and then charge huge amount of money for even simplest change requests. That ended once they start requiring that source code is delivered together with binaries. Open-sourcing apps is just one small step further in the same direction.