[morgo]

Being able to change it on a per connection basis is required for earlier applications. If we use Wordpress as an example, upon initial connection it will set the SQL mode to what it is compatible with (magento, drupal, others also do similar).

Integrity can also not be upheld if applications lie. i.e. I always enter the same incorrect birthday if an application asks me for this, but I don't think they have a reason for it.