I have struggled with the term "Mindfulness" myself for exact same reasons. However, through some readings and discussion, I came to think of it as "Self focus".
Random examples that worked to enhance my understanding:
- Meditation, which typically starts/involves training yourself to focus on something to exclusion of external distractions; frequently it starts with body focus - think of your breathing, think of your body parts. While I still suck at it, I do see the value in continuing the effort of being able to concentrate and focus on what I choose to,and not be continually a slave to random external (and internal!) inputs
- As a completely different example, my way of dealing with many difficult items was to "push them out of my mind". But that never really works for a long time. Being mindful of them to me means diving deep into the anxieties and issues, facing them and through them, and typically they become less scary afterwards.
- Related to both, being mindful of own body is a trick I started learning very late in life. But I now notice when my breathing patterns, posture, etc indicate internal anxiety or stress long before my conscious mind is alerted.
So I'm maybe 1% on my way through the journey, and approaching it from very much the skeptical/rational/scientific side, but again, I do see the value in the goal and method.
Not to say that there aren't million people/instructors/guides/therapists out there who DO make it into woo-woo! But like anything else, you can separate wheat from chaff with a little effort :)