Hi Jeremy - sorry for the delay in getting back to you. The permission settings for Google Docs require us to manually add each person to the access list, in order for them to see the solutions. We get
hundreds of requests for access to these files every year, which makes maintaining this list onerous. We could certainly make the folder publicly accessible, but then it would be trivially easy for students to get access to solutions.
Even if they were in a GDrive folder, however, teachers would have to click on each file to open them all. That's no different from clicking on each on on our Teacher Resources page. I agree that it makes downloading a little harder, but I'm not sure there's a better solution at the moment.
Definitely open to suggestions, however!