It is possible that this antenna is used for backup communication purposes (i.e. cellular) for an alarm system. Where I used to work, we did that at every building, in case the landline phone system took a dump.
I agree, since it's coming out of the room where the fire alarm is, likely it's for an alarm system, and simply being able to reach the monitoring point it's good enough.
Likely. But if all it has to do is beacon out a message to the central monitoring point at low power, it's not usually a big deal.
Also, usually installed by alarm guys, not to be confused with radio guys.
And most people don't want an "ugly antenna" on top of their building. And then the "if I put it below the roof line, it'll magically avoid lightning and induced energy!".
You're assuming that it's a "bad setup" without having the first clue what the purpose of it is for. Nothing but speculation here, hardly enough to draw any conclusions.