Microsoft enforced that and OEMs decided they'd rather build Android phones than Windows Phone ones. The rest is history.

I think having an OS available for free was more relevant.

Yeah, it's not like Samsung can go make iOS phones. And I highly doubt any of these hardware OEMs could possibly pull off a software project that doesn't suck, let alone a whole OS and dev ecosystem.

Samsung already releases phones running Tizen to have a side bet against Android. The quality of software is not very important when your only competitor builds phones that are significantly more expensive.

Tizen is a joke for app developers, it was already rebooted so many times, no one serious would spend a second trying to target the platform.

1 - Meego reborn as Tizen

2 - Tizen gets the Bada C++ SDK, with its Symbian C++ like flavour

3 - Enlightment guys join Tizen

4 - C++ SDK gets kicked out and replaced by Enlightment C libraries

5 - Developers complain that Tizen 2.3 drops C++ and is a C only experience

6 - Samsung announces support for .NET Core as high level native Tizen tooling

Really, what SDK are they going to release next?!

There was also a period of only allowing "HTML5 apps" (during the jQuery era no less) if I remember it correctly.

It is still the case when targeting Tizen TV devices.