As @mackiwg, I am also an educator by choice.
My first teacher position was extremely stressful. I was an undergraduate Psychology student with a lot of initiative but zero teaching experience. This is when and how I discovered Educational Technology. It helped be bridge some of the gap between me and the more-experienced teachers; but more importantly, it allowed me to envision a model where students had more agency over how, when and what they learned.
As I dug deeper, however, I stumbled with the other side of Educational Technology: the high-cost barriers, the proprietary issues on student-generated data, and the overall sensation of control (against freedom) that emerged from many of these technologies. For me, open(ness) represents an essential answer to this prerogative. So yes, open also matters personally to me. As a teacher, and as a lifelong learner.
Open means that a resource or a technology (or even, potentially, a praxis) is available for free (gratis), but it also grants freedom to be used, shared, remixed. This is important because, as stated in this lesson, knowledge increases when it is shared, and resources and technologies are enhanced when they are re-thought and re-designed through other eyes. My experience in teaching has taught me that. No content is ever delivered equally, it is constantly redefined and redrawn through the interaction of teachers and students. Open education promises to bring this dynamic to a bigger scale, by connecting learners throughout the world.