A lot of folks don't seem to understand that there's a separation between these three things. If you're good at one, it will make it easier to be good at the others. If you practice two, then you'll most certainly be able to apply that knowledge to catch up with the third.
The single most obvious difference I see when people argue their point when it comes to this subject - In a self defense situation, your first priority is to protect yourself. SECOND: Get away as fast as you can. If you're pulling guard it makes it incredibly difficult to accomplish these things.
Along those same lines - If you're hitting blast doubles then mounting your attacker for some GnP then you should be charged with aggravated assault and battery. That is NOT self defense. That is someone with something to prove. You must meet force with like force and not escalate. Protect yourself and run away. If you can't get away, then by all means, beat them up. But you almost always have a way out before serious harm has to come to anyone.
This is what is taught when you learn proper Brazilian Jiu Jitsu for self defense. There is no pulling guard. Going to the ground is the last resort. You learn how to protect yourself on your feet, finish your opponent while they're on the ground (sometimes while they're standing, too) and you're standing and GTFO of there ASAP.
In summary:
Guard pulling = Terrible for self defense. Can be good in sport applications - Emphasis on 'Can be good'.