There are ship fires every day - it's not that unusual. However, it is much more likely to happen than, say, a terrorist incident.
I see what you mean by the fire being violent, in as much as it can kill people, but there are already missions where you have to rescue drowning people from sinking ships. It may not be nice, but it happens in real life and therefore belongs in the simulator.
theres a campain for a cruise ship and it lights on fire!!! thats pretty violent!!! worse than a torpedo attack!
I assure you, it isn't. HMS Ocean has fires on a regular basis and she hasn't sunk yet.