I recently asked this question on twitter, but I thought to ask here again so that I have more than 140 characters 
I'm curious why the leaflet package isn't listed as part of the tidyverse.
I'm currently teaching a course on R. The first few days focus on tidyverse packages. Then I'm moving on to teach the leaflet package.
I think that a natural question my students will have it "Why isn't the leaflet package considered part of the tidyverse?"
I don't have a great answer for that right now, so I thought to ask here.
Thank you.
Ari