Just as wrong as someone walking in front of someone reciting Kaddish.
Whenever someone is reciting Kaddish, it is an Absolute No No to pass in front of the Kaddish reciter. One should imagine that there is solid glass wall in front of the Kaddish recite, and one simply cannot walk through glass.
I am shocked by how much disregard of this Halocho which I witness.
I am also shocked by people who sit during Kaddish, including even a Kaddish after a standing up prayer, whereby it is even more mandatory to stand up for that Kaddish.