How quickly did it spread through the bus, was in as bad as the gas, how often does it happen, and how much damage was there?
If it was slower to spread, happens at a lower rate, and caused less damage, then it's logical to consider not banning it.
With the gas, it seems to instantly engulf the whole vehicle and incinerate everyone on board. It also happens far more often (possibly every time one is involved in a collision).
I know you want to simply score points because you were embarrassed in an other thread, but you really should think a little before you comment. Logic is your friend.