In fact, there is a number of other dero nodes who are reporting the same blockchain as dero.tech, according to logs of my daemon.
I don't know why but they fail to synchronize, some of them get banned.
But how much of the total network hashrate do they command? If they only have a few kH/s out of several MH/s - like dero.tech - then they are wandering in the proverbial woods without a compass... I'm not saying this shouldn't get fixed, just that it's hard to get worked up over.