You are using open slots on other hosts that could be used by people who need to sync.
So you are saying that bitnodes abuses the network since it takes up a connection slot on all nodes.
What I fail to understand is how my node abuses the network, because even though it takes up a connection slot, it still has the full blockchain and can relay blocks and transactions.
It is a full nodeIf there are only a few who make this if not harmful, but if there are many of people (like >150) doing that all nodes would have more than 150 connections used for this and no more slot to serve the others (default settings is 125 peers max). With a bigger number maybe it wouldn't be possible to run a node with low hardware because there would be at least 500 guys who would try to connect to your node?