I can't help but notice that all of the historical concept art shows people sitting in one place while being fully-clothed and presentable. But phones have never been used that way at home. Even before wireless phones, people would buy extra-long cords for their phone handset so they could (for example) walk around in the kitchen preparing food while talking. And because phone calls are synchronous and intrusive, it's easy (and was historically common) to receive phone calls when you're not ready for video. I suspect that those two factors were at least as important as the high price in dooming any attempt at home video phones.

There's more of a case for long-distance video calls, but even long-distance voice calling was so expensive in the pre-cell phone era that it was rarely used for personal calls. Even the video calling we do today looks more like business -- scheduled conference calls -- than the personal phone calls of old.