I think it's seen as more effective because it IS more effective than many/most martial arts, especially in the shorter term. It seems like a program that was designed from the ground up to be nothing but effective for real life situations. There was no sport, no aim of mental or emotional development, etc. It was made for soldiers and law enforcement on the streets of Israel--people that need to be ready for knives and guns, in addition to fists and sticks.
Now, in the LONG term, I don't know. But, again, if the moves are so intricate that they aren't very useful for real world situations until you are 5 years in, or if they intentionally hold off teaching the most effective parts until you have shown the discipline and patience necessary for long katas, I don't think I'm that interested. I'm an impatient american, I want results NOW!
As for JKD, I agree that it's philosophy is similar, but it was never standardized enough to be accessible to many people.
And jiu-jitsu can be bad ***, but I've also heard some real bad *** people say that they would NEVER go to the ground in a street or bar fight due to the potential for biting, gouging, or a pocket knife you can't see coming, so a lot of the skills you learn there will probably go to waste if you have a confrontation (I'm not putting a mugger in an arm bar. That's dumb, haha).
So, that's my views. It's mainly a synthesis of what I have read, seen, heard, etc, as I don't have the time or availability to try all these martial arts myself. So take it as you will.