I wonder if that strategy is an unavoidable modus operandi, if so much of your management / work force motivation is derived from increasing the stock price.

...and at least consumers in that are not the customers, but the product...

The same strategy was pursued with Android. It was open-source, but Google set up the Open Handset Alliance with OEMs in 2007 and one of the membership stipulations were that OEMs could not create competing OSes based on forks of the open source code.

Over time, more and more functionality became linked to Google Play Services, which was not open source. The logical result of this was that OEMs simply went with the Google-approved proprietary flavour of Android.

How Samsung stay on while selling Tizen OS?

Tizen is a Linux foundation project, it's not an Android fork. In any case, Samsung can always arrange for preferential treatment as they are the flagship OEM.

I don't think any for-profit entity can be trusted with a monopoly over an important piece of infrastructure. It's healthy to have competing options.

It remains to be seen whether a non-profit entity can be trusted with such a position.