First argument: Jumping Guard On The Street
For some reason people watch BJJ matches between equally skilled opponents and think that because BJJ players are willing to jump guard in a tournament setting that they have no other options. The strict truth of the matter is that as a BJJ Blue belt 99.99% of people I meet have exactly ZERO defense against me taking them down. I have absolutely no reason to voluntarily pull guard against anyone in a confrontation. My takedowns aren't as good as a four year wrestler, or a four year judoka, but they are infinitely better than the takedown defense of almost everyone. So no, I will not be pulling guard on the street. I will be getting a bodylock and throwing you on your head, as will most BJJ people. And frankly, if a BJJ black belt wanted to he could pull guard in a street fight and crush pretty much anyone who is NOT a BJJ black belt or extremely high level wrestler without worrying about. It would still be a bad plan, but it's certainly doable at a very high level. Of course at that level your takedowns are even better, so once again you are likely to get spiked on your head instead.
Second Argument: Multiple Attackers
It has been stated many times that being on the ground against multiple attackers is a horrible idea and that BJJ has no way to deal with multiple attackers. The flawed thought process behind this argument is actually kind of mind bending. First of all, no Martial Art is going to allow you to effectively fend off half a dozen guys attacking you at once. If you are sufficiently skilled and have a good athleticism advantage you could probably take on two guys and win. If you're Cain Velasquez taking on untrained featherweights you can probably handle 4 or 5. But the mob is gonna bring you down one way or another no matter what. Krav Maga, Wing Chun, Muay thai, Judo, Boxing, BJJ, Wrestling, none of them will stop 6 guys from kicking your teeth in reliably. However, BJJ WILL help you avoid being held down, grabbed, tackled, etc... The ability to sweep and stand up if you get tackled is invaluable and the only way to truly learn it is to practice it against skilled, resisting people the way you do in a BJJ, Wrestling, or Judo class. So BJJ is AS good against multiple attackers as anything else. Of course, this entire argument is based on you being a MORON and going places by yourself where you are likely to end up in fights. I dunno about most people, but when I go downtown to party I usually have five or six friends with me, and most of my friends are trained.
Third Argument: Weapons
Going to the ground against a guy with a knife/gun/nunchuks/nuclear arsenal/etc is a terrible idea. That's absolutely true. That's why it's good to know how not to get tackled and pinned down by a guy with a knife. Knowing how to control someones limbs translates pretty well into defending against weapon assaults, but it's ALWAYS a terrible idea to get involved in a fight against someone with a weapon. Again, no martial art is going to help you against a guy with a gun if you don't have one. Nothing is going to reliably allow you to defend against a knife attack unarmed. BJJ is AS GOOD as anything else for weapon defense, which is to say, terrible. Of course, if you're a BJJ guy armed with a knife it's just that much easier to hold someone still while you stab them...
Really the entire argument is fallacious. The people making the argument are always proponents of some other martial arts system which they claim does the job better than BJJ, however those systems are things like Wing Chun and Systema which are unable to reliably handle a single unarmed opponent, much less two guys with knives. Which brings me to the most important counter argument against the "Deadly" systems. Because some practitioner of one of the arts mentioned here will tell me that their art is too dangerous to use in the ring I'm going to discuss the Force Continuum.
The Force Continuum
BJJ is an EXCELLENT art for self defense. It teaches you to control your opponent, maintain a dominant position, and apply an appropriate level of force ranging from passive restraint all the way up to a fatal choke.
If your drunken cousin starts a scene with his girlfriend at your sisters wedding is it REALLY appropriate to kick him in the nuts and gouge out his eyes? If your 6 year old is throwing a tantrum is the best solution an elbow to the spine? If you said YES! Then you're a psychopath. The answer is NO. Those are not appropriate reactions. But many arts would have you believe that they have no tools beyond those deadly strikes. They have no ability to restrain an opponent that doesn't result in crippling or fatal injury.
With BJJ you can choose to act anywhere along the force continuum. If I need to hold down a hysterical 6 year old I can do so without injuring or even hurting him. If I need to escort my ranting cousin out of the wedding I can do it without putting him in the hospital. But if some guy starts trying to cave my face in I can break his arm or choke him unconcious. Bottom line, BJJ and Judo are both ideal for self defense. The best solution for self defense though is BJJ, Judo or Wrestling and Boxing, Muay Thai, or another solid COMPETITION striking art like Kyokushin, combined with conflict de-escalation and avoidance training and a little common sense.
But most importantly, follow the cardinal rules of not getting your ass kicked:
1. Don't go places where you might get your ass kicked.
2. If you violate rule 1, don't go alone.
3. If you violate rule 1 and 2, don't get drunk.
4. If you violate rules 1-3 then there's a good chance you'll get your ass kicked.
The hard fact is that most people will never ever be in a life or death encounter where eye gouging or trachea crushing is the correct response. Your cousin larry gets drunk and starts hitting on the brides mom at your brothers wedding? EYEGOUGEGROINKICK! Is not the appropriate solution.
There, now I can just link this post in the next retarded BJJ Self defense argument.