Gaaf! De kende ik nog niet
Maybe that's not true... https://youtu.be/h6fcK_fRYaI
I think you make a good point regarding support. This is, for businesses, the crucial issue. They want to buy reliance, support and certainty. This is what commerce, like Microsoft, offers; peace of mind for (big) bucks.
Organizations can't easily take measures to assure proper support for a lot of open source software. They'd have to hire and probably educate a lot of expertise, which all has to be managed too.
It's just a whole lot easier for decision makers to spent extra money to have a contractor solve any issues, or at be able to blame (sue) them.
They explain it's different, because people still prefer not switching to an alternative even if it's without any cost
I'm sorry Dave
This is close to my personal take on the subject; "you don't turn on your signal for the car you saw, you do it (especially) for the car you didn't see"