If a person is using a fluffy watered down definition like "being mindful", I'd be awfully curious how that would differentiate from any of the bazillion other philosophies that are basically that as well. How is that any different than, say, ChooseFI philosophy, or even zen buddhism, or Marie Kondo/minimalism?
It seems to me like the definitions that so many people in this thread are using are actually way more in line with ChooseFI than MMM. I'm not saying that like it's a bad thing, just different. ChooseFI is definitely heavy on mindfulness, conscious consumerism, etc, while MMM is way more facepunches, get on that bike you clown, DIY, be a badass, etc.
Personally, I prefer ERE philosophy, which takes it even further into crazy-land where spending levels are compared by JAFIs (1 Jacob Adjusted for Inflation = about $8,600/person/year spending level including everything), you build your own furniture, spend $100/month on food, and basically eschew consumerism altogether. But this place is cool too.