there is a new feature request to add the FreeDNS servers.
We can't and shouldn't add all the thousands DNS servers out there. We maybe should specify some minimal criteria for new (and currently added!) servers:
no logging
no censoring, no filtering (ads, blocklist, ...)
no interception, no forwarding (info page on misspelled domain, ...)
Sounds good, for a Project it makes sense to have open source projects listed as the built in DNS options such as FreeDNS / OpenDNS, as not everyone knows about them, at the very least it would give a bit of advertising for them.
But what about the fact say people use Google's DNS a heck of a lot and we know its monitored like hell, i do agree the default built in ones should be as Mibere has mentioned.