Thats more clear, I get your point now. Again, though, that's not how most people would read the original comment. I've never even contemplated that I might generate some hostnames existence of which might be considered sensitive. It seems like a terrible idea to begin with, as I'm sure there are other avenues for those "secret" domains to be leaked. Perhaps name your secret VMs vm1, vm2, ..., instead of <your root password>. But yeah, this is not my area of expertise, nor a concern for the vast majority of internet users who want more privacy than their ISP will provide.
I am curious though, do you have any suggestions for alternative DNS that is better?