Reddit reviews The Meditative Mind: The Varieties of Meditative Experience

>Why are there so few comparative resources

Lots of the popular, definitive, comprehensive paths/techniques are built so that you can jump in and stick with it. One byproduct of that is that some people can get the sense that there's nothing else out there if that's all they stuck with. The comparitive-resource-stuff is good for academics, or adventurous types, or experts who want to 'make their own' techniques, but for a lot of people they just want something that makes them feel better, and if they find that, then stopping what works and turn to textbooks and videos about history and culture doesn't add much (I speak as a fan of jumping around, just generalizing).

>Are there Intro to Meditation classes or books that expose students to a few different styles

Try--> 'The Meditative Mind: The Varieties of Meditative Experience' by psychologist (and meditator) Daniel Goleman

>encourage them to seek out more information on the one that works best for them

It's not that teachers discourage seeking information, they just work with what they know and promote what has worked for them. That can look like bias for their style, and that can happen a lot, but a lot of the time it's just the teacher/students being fans of that approach.

>Why are teachers (and some posters in this sub) so reluctant to label the style they're teaching?

I'm not sure what you mean. The label depends on the context: must I say that I practice 'mindfulness,' because it's also called Satipatthana, by others it's called Vipassana, or maybe I should turn around and take the National Institute of Health's label of 'open monitoring' style... I find that getting into the labels isn't as helpful as just dealing with you as an individual, speaking about consciousness, attention, health, and wellbeing based on your tradition of choice.

>Many Eastern traditions, like Yoga, Zen and Taoism, incorporate a range of styles, but in the West only a single style from each of those traditions is popular - why is that

What do you mean? You said 'Eastern traditions' have a range of styles. Ok. Next, you say one single style (of each tradition?) is popular? So are you saying that only one style of Zen is popular in the West, one style of Yoga, and one style of Taoism...or are you claiming that each of those traditions is syncretic in some way in the East while in the West we don't add-in things from the surrounding regional culture/et-cetera?