Black Tea is the nourishing mother of all teas. For so many people (in the West) it's the safe, go-to tea, you know what to expect and you have an idea of what you are going to receive. There's not a lot of surprise, and from this perspective it's a tea that most people are most open to trying. It's not going to stretch us to much outside of our comfort zone and it's name alone is familiar.
That said... it's not about judging the tea style one choices to access the divine. Instead, it's just about observing the choices we make and being conscious to them in the moment. It's a practice and an invitation.