You seem to have this retrospective view of technology creation where anything that didn't pan out or doesn't connect to current technology was therefore a waste of time and effort. The problem is that at the present nobody knows what's going to work out- you just have to try. Some ideas will work, some will not, some ideas will be lost and then re-discovered. It's a messy process. I'm sure there are robotics researchers who are wasting their time in dead end technologies. But I don't know which ones they are, and neither do you. I have opinions, but I'm not prescient.

People thinking about them helps. You don't need the first people designing computers to have heard of an analytic engine and be working from Babbages notes for there to be dependencies. And it is not as though Babbages work did not have an influence on mathematics and technology in its day, it was widely known and discussed in both academic and political circles, and will have certainly influenced many. It would seem unlikely for the people working on the first working computers to not be drawing on some work that had echoes of the earlier attempts in the field, irrespective of whether the researchers themselves were aware of it.