Good question. We have to be kind of careful. My intention isn't to be vague, but fraudbusting is frowned up. So, I end up sounding a little passive aggressive.
I'm talking about folks who say things like, "We don't train to fight. We train for self defense," who will also talk about how they never fight (and in some cases, have NEVER fought). These guys will also often describe their own training as being "effective" on the street, and will opine about what works and doesn't work in a "real fight."
To be clear, it's not style specific. It's training specific, though some styles definitely embrace a lack of application as a feature and not a bug. This is a great example of how, if you train for some application, your style can work great. But this is true in the converse, as well. It's the application that makes it work, not the style. So, if you train white crane, wing chun, ninjutsu, or aikido and apply the skills, the PEOPLE who train in those styles will learn to apply the skills. And the inverse, if you train in boxing, MMA, BJJ, wrestling, or kickboxing, and remove the application, it will pretty quickly devolve into something that barely resembles "effective".