Screen shake itself isn't much of a problem when you're near an explosion or maybe near the impact of a blaster, but there are some things in the game that excessively shakes the screen that becomes very irritating after a while.
The Mixmaster-type weapons, these are also very obnoxious to play with- especially if you aren't the one using it. The bullets fired from this gun causes the screen to shake for many around the user when they impact something, these guns fire 6 shots rather than 3 like other blasters and guns that shake screens. What makes Mixmaster-type weapons worse is even when you miss, the bullets fired from this gun return to the knight that fired it and impacts them, also causing the screen to shake. This makes playing with knights that wield this weapon insanely irritating with consistent screen shaking through entire maps, and with these weapons being one of the "most powerful" guns in the game, knights are definitely going to want to use it over others.
It sucks for them if they get booted from lobbies and missions for using them though, it is definitely not fun for some knights to be playing with others' using these guns.
I do not frequently see demo-knights, but I believe bombs in the Blast bomb line cause some amount of screen shake, it would also be bothersome to be playing with knights that spam weapons such as these.

I would like to see a way to disable this shaking, or have them greatly reduced to make them less obnoxious and intrusive to play with. I can just leave squads or kick knights that I wouldn't want to play with, but that wouldn't be fun for anyone.