How Realistic Are the Kumite Drills

I am going to focus only on two, the full nelson and the bear hug attacks. Now, this is going to be short, in my personal experiences I have never encountered nor witnessed an attack by anyone where either of these attacks are used. I also count any YouTube video's I have viewed that "say" they are fights, attacks or self-defense situations. There are many out there to view. I also count the professionals I follow in books and on the Internet as to web sites and blog posts, etc.

I don't believe they are realistic self-defense training drills. They are easy to teach and they will look and feel good to those who have never been attacked or in a real fight, i.e. not some social monkey dance but a real fight. I am making some assumptions with only a minimal amount of experience. One incident was a monkey dance with a crowd and the two fighters never once did a bear hug or a full nelson. 

Granted, a full or half nelson may be applied in sport especially with those who practice and train at ground work, etc. but still not in a fight on the streets as far as I know. Maybe others can chime in with details as to the fights they have been in where either or have been used "in a fight." 

If the system you practice uses these types of kumite drills for posterity and historical preservation purposes then all is well. I speak up with my opinions when I feel that the participants are "assuming it is for real self-defense." 

Then again, just because I have not witnessed such a thing or observed it out there in the world does not mean someone somewhere has used it, and successfully. I just have a hard time picturing or imagining a predator attacking a victim with either of these techniques. But, hey, I can be very wrong, right?

p.s. Even in the training hall I have never witnessed anyone teaching how to defend against a predatory surprise attack, i.e. like coming up behind an unsuspecting victim and smashing them in the back of the head with a brick type thing - hmmm, wonder if a true predator would use this to get what they want? Hmmmm .....