Just because they are called “public” it doesn’t mean they’re owned by the public. It’s a non profit created to produce media for public consumption, but they still have bills to pay, employees, etc.

If they have content for streaming or DVD sales or (probably more likely) licensing to other PBS stations, they need to get income from it to maximize their ability to continue to produce the free broadcasts they were created for.

Mr. Rogers would surely approve of sharing for the common good.

Correct :)

If their funding was 100% paid for by taxes, sure. But only a small fraction is actually paid for with public funds. They have to earn the rest to stay afloat.

There’s that, and also part that’s donations by viewers and sponsors. While they need funding to maintain operational costs I don’t think they have the typical pressure of expecting a return on investment to deal with, so volunteer supported archiving, hosting via things like peertube or youtube without needing to show ads, there’s room for some novel operations that other content producers don’t have.

None of it is solely funded by CPB. This is Nine PBS not PBS. 50TB is very low for broadcast footage so it’s likely a small handful of local shows, and a partial archive at that. For context, a 2000s consumer camcorder tape was 17GB per hour.