I don't deny the possibility of not coming across a good Wing Chun school. I'm curious to see the example you've come across to see how they're different.I think you just got exposed to crappy wing chun. If anything, the wing chun I've seen had an over-reliance on structure and accompanying hand techniques, but if you were dumb enough to stand in front of them, you were likely in for some hurtin'.
Overall, I think good schools of any classical martial art are pretty hard to come by. The "average" is likely a pretty poor representation of any real quality school, in the same way that the "average" taiji school is not representative of the art as we know it 'round here.
The most popular Wing Chun came from Ip Man, so it's really just one branch that got most of the spotlight. Recently, there's been more exposure to non-Ip Man lines and there are a lot out there. Unfortunately, with the boom from the popularity of Ip Man movies, there's also a lot more BS as well making the signal-to-noise ratio worse.