In the real world when lives are on the line, techniques like kicks, punches, wristlocks, eye gouges just aren't used effectively. Brazilian Jiu-Jitsu focuses on simple moves with large body movements that can work under pressure. They can be practiced against fully resisting opponents so you can see their effectiveness. They can't be mastered in a single class, but you won't be walking around with false confidence that other martial arts techniques might give you.
Our US Military now teaches the Modern Army Combatives program which is based on the combatives program of the Gracie Family and Brazilian Jiu-Jitsu.
Abstract : Despite technological advances, hand-to-hand combat remains a persistent aspect of the contemporary operating environment (Wojadkowski, 2007). To develop a more detailed understanding on the use of hand-to-hand combat, the researcher analyzed 30 Post-Combat Surveys administered to US Army Soldiers from 2004 to 2008 after their return from deployments to Iraq and Afghanistan. 216 out of 1,226 Soldiers (19.0%) reported using hand-to-hand combat skills in at least one encounter. The Soldiers descriptions indicated that hand-to-hand combat occurred in a variety of tactical situations and that the most common skills employed were grappling techniques (72.6%), followed by the use of weapons (e.g., rifle butt strikes; 21.9%); with striking as the least reported skill (i.e., punching and kicking; 5.5%). These results further reinforce that hand-to-hand combat remains a relevant demand and the US Army should continue such training with an emphasis on grappling skills practiced across a variety of performance settings.