Inside-to-inside NAT aka NAT loopback solves hairpin NAT issues when accessing a web server on the external interface of an ASA or similar device from computers on the internal interface. This prevents DNS admins from having to maintain a duplicate internal DNS zone that has the corresponding RFC1918 addresses for their servers that are NATted to public addresses. I'm not a network engineer, so I might be missing something, but this seems like a no-brainer to configure and implement. Asymmetric routing can be an issue but is easily mitigated.
In my experience, network admins/engineers prefer that systems folks just run split-dns rather than configuring their firewalls to properly handle NAT hairpins. Why is this?
ad.example.com
or similar (like it should be!), then this problem will exist for all publicexample.com
DNS entries and nothing internal is published externally. Of course, if you've named your AD the same as your public presence you must use split-DNS, but that's not a best practice AD design.