Are You Trying to Separate Mindfulness From the Theory?

To what degree is Buddhism some sort of package deal? I've had Buddhists suggest to me very politely that you can only get that far in your understanding of Buddhist philosophy if you don't actually practice Buddhism. On the other hand, it's interesting because a lot of support is coming from clinical psychologists for the use of mindfulness in therapy. So those contrasting views and all I can do is kind of state them without really knowing which one's a support.