"""Sorry mate, ever heard of vendor lock-in ? This is what happens adopting closed source technologies, they sounds great to start, then ... here you are."""

So, you didn't really understood that part where he wrote that for their specific requirements Flex was better suited, and enabled them to deliver stuff that they couldn't otherwise (at least without much pain)?

Also, yeah, it's like this kind of thing never happens to open source projects. Like, for example, the community loses interest and moves on, or decides to change the direction of the project to something you can't work with and don't care about, and the old platform you were building on is suddenly left to digital rot (no new features, not adapted to new environment and os releases, no more fixes, etc).

Sure, you still have the source for the old project.

But it's damn near useless unless you have the will, the knowledge, the time, and the manpower to fork it and adapt it to your needs, or the money to pay others to do it.

You have to understand that living at the whims of a volunteer community has it's own drawbacks, compared to living at the whims of a commercial company.