Customer Access to Modify DNS

[lilith at paxumbrae.com]

I am interested in collecting fact-based reasons as to why it would be a
bad idea to allow customers to modify their own DNS zones through a
webpage or dynamic updates. If there aren't any, I am interested in
knowing that as well.

I am interested in doing what is best to preserve data integrity and
security, and it seems to me that allowing customers who may not know what
they are doing the opportunity to access such sensitive data is asking for
a lot of support calls, especially in allowing them to modify in-addr
zones which they may only own a handful of addresses in.

How prevalent is the policy of mandating that customers must run their own
nameserver if they wish to administer their own DNS? Could this be
considered an industry standard?