Fighting in angles

Hi all,
I just finished a Tae Kwon Do lesson and i was shocked. Everyone fights in line, they dont know how to move around there opponent. Im not saying that only Tkd does this i have seen Karate students do this aswell.
A black belt student fired a side kick at me and i jumped to his side and roundhoused him in the gut. I did this 4 times. He just wouldnt understand that fighting is 3d not 2d.
Has anyone else experienced this.
ps. Im not bad mouthing Tkd or n e other martial arts.
Oli

Yes its a typical phenomena with many 'modern karate' styles. I think the root of it lies in the fact that Funakoshi removed many of the 'entry' techniques from the kata. Heian has no 45% entries whereas Pinan has lots.

It is also largely due to the fact the free-sparing kumite of Shotokan was modelled on both Kendo and Judo (scoring and technique)
This was so karate (originally Okinawan) would be more widely accepted by the Japanese.