I am not suggesting that the copyright should belong to anyone else besides Krüse. He remains the sole holder. But he has made it impossible for those of good faith to register the software: the site no longer exists, he doesn't respond to any question whatsoever. He doesn't even issue a public statement clarifying the status of the programs. Now, he doesn't need to do that, since the laws which apply in these situations are very strict. Nevertheless, I am at liberty to say I am not happy with this particular situation, even though it will be irrelevant in five year's time (who will be using Miami then), and academic by the year 2070 (when the code officially becomes public domain). I recall that the US government installed a working group not too long ago to see what could be done about this problem: it is not just Miami.
Perhaps it is exactly as Krüse intended... But we will never know, as he no longer responds. That is why I consider Miami 'abandonware', even though the term has no legal basis.