While it's definitely true that the less you engage with the material, the less you'll get out of it, it also sounds like the group leader doesn't want to engage dissent. So where does that leave you? Quiet and resentful.

I'm surprised there isn't homework--like a workbook; I thought that was pretty standard with DBT.

The only thing I can think of would be to speak to him outside of the group meeting and tell him your perceptions. What suggestions would he have for overcoming your resistance? Ask him for specifics of how to apply these skills in your daily life. Give him examples of situations that are difficult for you and ask which skills you should use and how to do it. If he says something like, "well, you just have to decide to accept it" then you know he's not going to be very helpful to you.