I have people that ask me to open-source my current side-project all the time (one that is paid), and I find it insanely disrespectful.
"Yes, let me just hand over the source code for my commercial product. How about not."
I'm not trying to sound greedy, but money speaks. If these companies want the software open sourced, they should be pitching in for the cost. If you don't think something is worth money, you don't value it at all.
EDIT: Perhaps this is a good place to drop the "challenge" I gave myself and invited other developers to join me a few months ago.
DEVELOPERS - I challenge you to spend some money TODAY:
https://mattkremer.com/developers-you-need-to-stop-being-so-...