Trained Wing Chun for 3 years. Recently doing more MMA type stuff, amongst the guys I came across most of them also did Wing Chun and jumped onto the MMA bandwagon. What surprises me I always get similar sorts of Wing Chun criticisms from most. This is a cause for concern because unlike other CMA, Wing Chun is indeed a pure fighting system. And was always being constantly 'combat' refined by the likes of Yip Man during the Hong Kong heydays.
.........
From a person who has a bit of sparring in Muay Thai, Judo, MMA, San Shou, judo and BJJ matches and trained extensively in Wing Chun, "The way Wing Chun is taught traditionally is not conducive to any sort of situation, either sport fighting or self defence.
The problems I’ve noticed are as follows: The Trapping range is an inferior substitute to either a wrestling or Thai clinch. Instead of controlling the body and the head like a clinch does, Wing Chun seeks to control the limbs, which is hazardous against any opponent who doesn't make a bridge and is competent in basic boxing and even more dangerous against any semi-competent clinch user. It’s hard to “stick” to someone who is fighting in a more boxer like style as they simply retract their fist immediately after striking instead of trying to form a “bridge” with their opponent. If you do manage to close the distance enough to use Wing Chun techniques you will probably just end up clinching and falling to the ground anyway.
On Wing Chun's method of punching , Great emphasis is placed on attacking the centreline with sun punches, but neglected are looping punches, hooking punches, and uppercuts. Also neglected is effective use of angles (not all lineages). Although many Wing Chun schools promote the use of intercepting angles to set up clean strikes, there is little actual training that creates this skill, unlike boxing slipping and footwork drills.
At the schools I trained at, Wing Chun stylist typically had a problem defending against looping punchs. The reason I think this happens is because most Wing Chun guys train with other Wing Chun guys, and since none of them train with hooks, they never really get that good at defending against them.
Additionally, the way punching is taught at the majority of Wing Chun schools I've been to leaves one open for counters. The punch is thrown with the shoulder down, as opposed to covering the face. The opposite hand is often held above the bicep to intercept a counterpunch, but as can be seen by anyone in sparring, that's hardly fool-proof. The shoulder being down prevents any kind of shoulder protection or shoulder roll. Coupled with the fact that the Wing Chun stance is taught with the chin up, in a 'neutral position' rather than ducking your chin, and this punch just does not stand up to scrutiny.Wing Chun teaches to keep hands at around chest level instead of up by their head.
My other critique is that the Wing Chun stance of many schools is not very mobile, hard to sprawl (most weight on the backfoot) and not set up well to deal with grappling. Wing Chun's reliance on footwork as a defensive tool is admirable, but is often overcomplicated and not drilled practically. The fighting range for wing chun is what would be the clinching range for most other styles, so it is a bit strange that grappling (apart from chin-na) is largely absent in traditional Wing Chun.