You seem to forget that Domain Name Resolution became a problem after the more generic Name Resolution (ie Novel/lanman/NetBIOS). The Generic Name resolution system used lmhosts, which became hosts to more easily associate IPs and names. [0]
> Originally these names were stored in and provided by a hosts file but today most such names are part of the hierarchical Domain Name System (DNS).
The lack of trust I mentioned was about ISP provided DNS servers. You don't own your WAN network and the majority of people use the DNS provided by their ISP.
On your own network, if you feel like doing a DNS lookup to what amounts to a public address book is unethical then don't allow arbitrary clients on the network.
If you want to do blocking based on a DNS list, configure your firewall to do that.