George S. Ledyard
There is a difference between the issue of what constitutes an "effective" martial art or an "effective" practitioner of that art.
As Ikeda Sensei says, "It's not Aikido that doesn't work; it's YOUR Aikido that doesn't work.
For a while that statement made sense to me. Then I began to think that if that statement holds true for Aikido it should hold true for many other arts as well:
"Judo works; YOUR Judo doesn't."
"BJJ works; YOUR BJJ doesn't."
"Boxing works; YOUR Boxing doesn't"
However you see many more Aikidoka that the above statement applies to than practitioners of the arts I mentioned. Judo, Brazilian JuiJuitsu, boxing, kickboxing, muay thai, MMA, Kyokushin Karate, and many others produce people capable of defending themselves using their art in a short period of time. A major reason is their training methodology. Boxers use a heavy bag, speed bag, headache bag, and shadow boxing to learn the basics and then they spar. Judoka use an uke/tori relationship in uchikomi practices and then they randori. Kyokushin Karateka use kata and bags and eventually spar. Aikido never seems to move beyond the uke/nage relationship. Even jiyu-waza seems to lack the same feeling that I experienced in Judo randori.
Regardless of whether you call your style a martial art, combat system, or fight sport most people enter under the pretense that they will develop skills to allow themselves to overcome one or more opponents in an unarmed confrontation. This is in fact the selling point for many styles, especially those claiming reality based self defense. The problem is that many of those that claim effectiveness do not deliver. Students are often deluded as to their capabilities and these delusions could place them in a potentially deadly situation.