That was pretty well de rigeur for scientists and philosophers up until the 18th or 19th century. No one wanted to be the next Galileo.
I have no doubt that many of those thinkers were profoundly religious and some others weren't, but that's impossible to glean from their published writings. The effort to jibe with the dominant theology of their places and times was par for the course, and in some cases the efforts to explain that their findings did not clash with church teachings -- which, frequently, they clearly did -- involve some tortured logic.
Something I would not expect to see on PBS.
You can't begin to cover the early history of science without talking about religion, which at various times served as both a history and an impediment.
I do not agree with some of the ID teachings, young earth for one, but I see no harm in presenting it as another "theory".
I have no problem with teaching it as a theory if it ever becomes one. As it is, it's just a belief without any scientific foundation or means of testing it.
One wonders whether they can boil water without burning it.