There has been much discussion and complaints about kids that are involved in year around wrestling. The kids that I have seen wrestle year around do this 1 night per week for around 2 hours each practice during the off season. They also still play other sports. I don't consider this to be specialization and feel it is good for a self-motivated kid that wants improves. Not sure why someone would think this is hurting the sport? Wrestling is a tough, complicated sport and it may take extra work for some to achieve success in wrestling.
Do Karate classes, gymnastics etc. only practice 3 to 4 months each year? I don't believe so, they go year around.