I was a big fan of the Public Interest channels myself. Unfortunately one of the best, DOC TV, was bought out by Pivot, which is not bad, but also only available with a fairly pricey package. Pivot also seems to want to be more of a general audience channel. And FSTV and Link TV both used to show more documentaries than they do now. FSTV now seems more like a news channel to the left of MSNBC, because most of their schedule is now live/simulcasted radio shows during the day Mon-Fri, and they have cut back on the documentaries and other series they showed years ago. I would guess that the simulcasted shows are probably cheaper. Link TV, I had high hopes for since they were bought by KCET Los Angeles, but again, it seems like they have lowered the number of different programs/series they show, and instead they repeat the ones they have more often. Again, a cheaper way to fill the airtime, but not as good as what we had years ago.
In more recent years, since the Sky Angel contract has expired (which prevented Dish from adding very many religious channels as PI), it seems like most of the PI channels have in fact been religious. The Sky Angel contract, although some complained that it forced Christian channels into Sky Angel, also had the benefit of forcing Dish to work a little harder and come up with some better secular educational programming to fill the required PI channel spaces.
FSTV also has a Roku app with a live stream. Link TV just added a Roku app about a week ago, but it only has on-demand content, no live streaming so far. You might also check out MHz WorldView for similar type programming. WorldView is carried as a PI channel on DirecTV, but not on Dish. I think they were extremely close to being on Dish and then got dropped for some odd reason, right before they went on air.
