KiCad already has too many annoying popups.
Also, such warnings imply some fixed workflow. For example when I just want to create a pintout to do some test fitting of footprints then I am not interested in whether DRC works at all.
Ordering PCB’s cost money, and delays costs time which can also cost money. It is common to make a checklist and go though the checklist before PCB are ordered. Similar to pilots. They always run though a checklist before they start a plane and takeoff.