We all do it - search on google for a tool to help us with some task or another. And when we find a free system ... well, it doesn't cost anything so "why not give it a go?".
Download, install and ... it's great. Exactly what you needed and cost you nothing. There was a "donations" button - but you can't really be bothered with that.
For example, I use WinZip, to manage compressed files. Occasionally it reminds me that they'd like me to make a donation but I can't be bothered. It does what I want and that's enough.
Now, imagine if other businesses did this! How about coffee shops? Walk in and just get served free coffee! With a "donations please?" box at the end of the counter. It's not difficult to see the insanity that would follow - coffee shops closing, staff wages slashed, quality and safety compromised.
At no point would it stop you actually choosing the free coffee (until it was no longer there!) because it obviously isn't a sustainable business model. Obviously (!) it will eventually collapse but what if it lasted long enough that there are now no coffee shops left!
Some would argue that "free coffee" is therefore immoral. At the very least it is unfair competition and therefore anti-competitive!
Software is the same. Open Source is bad for this industry and inevitably bad for users. How bad is it for the software industry? Check out this News Article on "The Register"
For example - 50% of Open Source Projects can't sustain their maintainers above the poverty line! Even we (as software developers) contribute to this shocking situation. We use "OpenSSL". This project was earning $2,000 a year, prior to 2014 - at which point a significant security vulnerability surfaced! And even now, it has a ridiculously low income!
If you are considering committing your organisation to Open Source Software, think "sustainability" before you leap! Read the article in The Register, as a very minimum - as you take a sip from that cup of coffee you just BOUGHT, sitting in your favourite coffee shop!