Re libosmscout: I decided to maintain only the backends which I think are the best and which I am using personally. I believe that, without personal usage, I cannot monitor nor fix the issues occurring with the backends. In december 2017, I asked for help in maintaining libosmscout in the corresponding developer list and most probably notified here as well. So far, nobody has stepped up and worked on upgrading the backend interface to the newer versions of libosmscout.
Re name OSM Scout Server: yes, its long. And there are historical reasons for that. However, rebranding is significant work and there should be initiative / reason for it (github and transifex repo, pointers at openrepos, docs, aggregation lists and such would have to be changed). And this work will have to be done instead of the development.