DNS is a wire protocol, payload specification, and application protocol. For all of that, I personally wonder whether its enduring success isn't that it's remarkably underspecified when you get to the corner cases.
There's also so much of it, and it mostly works, most of the time. This creates a hysteresis loop in human judgement of efficacy: even a blind chicken gets corn if it's standing in it. Cisco bought cisco., but (a decade ago, when I had access to the firehose) on any given day belkin. would be in the top 10 TLDs if you looked at the NXDOMAIN traffic. Clients don't opportunistically try TCP (which they shouldn't, according to the specification...), but we have DoT (...but should in practice). My ISPs reverse DNS implementation is so bad that qname minimization breaks... but "nobody should be using qname minimization for reverse DNS", and "Spamhaus is breaking the law by casting shades at qname minimization".
"4096 ought to be enough for anybody" (no, frags are bad. see TCP above). There is only ever one request in a TCP connection... hey, what are these two bytes which are in front of the payload in my TCP connection? People who want to believe that their proprietary headers will be preserved if they forward an application protocol through an arbitrary number of intermediate proxy / forwarders (because that's way easier than running real DNS at the segment edge and logging client information at the application level).
Tangential, but: "But there's more to it, because people doing these things typically describe how it works for them (not how it doesn't work) and onlookers who don't pay close attention conclude "it works"." http://consulting.m3047.net/dubai-letters/dnstap-vs-pcap.htm...