Star Trek? Star Wars? Harry Potter? Lord of the Rings?
There is a lot of entertainment out there which (depending on your particular set of morals of course) is clean and entertaining. The problem is, as I said above: good entertainment needs conflict. You can imagine a make-believe world where the reaction to conflict is all nobility and righteousness, but by and large that is highly unrealistic. And so, if you want that kind of entertainment you need to have it set in a universe pretty significantly divorced from our own.
And, yes, "Little House on the Prairie" is just as imaginary a universe as Lord of the Rings. That world never existed. IMHO, it has caused significant trouble in the US because it convinced a large portion of America that back in the "good old days" life was much better and "simpler" than in the modern day (thus if only we get rid of all the features of the modern era we can return to that simpler time). But soapbox aside, those two shows were set far enough in the past - a past in which your pious and wholesome grandmother grew up, or perhaps her grandmother - that they could pretend things were much different than they really were. This allowed low-grade conflict to be resolved with no more violence than a punch in the nose and more often than not a strident speech which brings everyone to their senses.
Now the problem with a show like that is that you know exactly what to expect. I grew up when those shows were on the air, and while we had them on each week, they were never considered "good" entertainment. You knew exactly what was going to happen. There is no character growth. You can't relate to the characters. Today we have much more to choose from than three channels with varying degrees of reception clarity. There is a lot of entertainment out there with relatable characters who grow and change. But it is incredibly hard to have a growing, changing set of characters who are never allowed to do anything that might challenge the viewer's morals.
It's like how my mother used to describe Stephen King stories. "Really good and exciting, but did they have to curse so much?" Well, yeah, they kind of did. A rabid dog keeps you stuck in your car for days on end, would you react with "golly this is gosh-darned horrible!" or maybe lay out a few expletives at the beast? Characters need to be relatable, and being relatable means sometimes not choosing the best thing, sometimes making mistakes.
