Samsung doesn't own Tizen, although it's loosely based on a very old Samsung linux project and in 2013 they merged in the functionality that existed in Bada. They are one member of the Board of Directors for the Tizen Association (1 of 10) and one of dozens of partners and hundreds of member companies. Samsung and Intel are two big players in that game, but they're still merely players. The current Board of Directors is Fujitsu, Huawei, Intel (Officer), KT, LG, NTT DoCoMo (Officer), Orange (Officer), Samsung (officer), SK telecom and Vodaphone. Samsung competitors (obviously LG, Huawei, etc) such as Panasonic, Sharp, ZTE and many others are also partners in the project, just as Oracle, Sprint & and Coremob.
Many of the partners (including Samsung, Intel, Nvidia, Qualcomm, Motorola, LG, HTC, Sprint, Tmobile, NTT DoCoMo, Vodaphone, Huawei, Sony, ZTE, etc, etc, etc) also are partners of Sailfish, and the Open Handset Alliance and through that the Android Open Source Project.
Tizen is really just a rebranding of the Linux Mobile Foundation, which includes all of these same players and which was founded with Samsung, Panasonic and Motorola working together in 2007 (along with - again - dozens of other partners, most of which are still on the rebranded project roster).
Here's how these things work: someone has an idea and says, "hey, lets group together and make something we can all use" and all of these companies jump on board, even if they contribute little, because the benefits of being part of the project should it take off outweigh the cost of sitting through a couple of meetings.
None of that makes the project good or worthwhile or anything and today Tizen has more in common with Cyanogenmod or Paranoid Android (for different reasons) than with Google's Android and accompanying OEM partnerships, as a platform. If OEM's start making devices in any meaningful way it will start to show similarities to Windows Phone, in terms of share, market impact and ecosystem.
I realize Samsung is a major player in bringing Tizen to devices in the market - but thinking of this as their creation to lash out against Google is simply insane. They're diversifying and supporting multiple projects as they have always done (see Samsung Windows phones, Samsung Bada phones, Samsung LiMo phones, blah, blah, etc, etc). HTC, Panasonic, HP, Sony, etc, etc have all this in common and it's smart business to have multiple streams of contact with the market.
What would be stupid beyond all belief would be to burn bridges with 80% of the world in order to promote one of several projects that you're a stakeholder in - specifically one that has no traction (as of 2014, ).
Bottom line: These are both open source projects (Android and Tizen) and they have almost identical rosters of companies supporting them. If Samsung releases Tizen devices, it will have approximately the same amount of control over Tizen as it does with Android with the exception of the requirements that are in place for OEMs who wish to license the Google Play store. It doesn't get to shape Tizen to fit Samsung's needs any more than it got to shape Android to fit Samsung's needs (note that it did that a lot in the form of TouchWiz - same level of concept here).