They wanted to drop water but couldn't because of the drones. Why, they were afraid they'd damage the drones in putting out a fire? Solution, drop water on the drones.
I'm sure helicopters have to deal with birds sometimes. These drones don't appear to be that durable or heavy, are you telling me that the propeller blades can't handle these little things without causing a disaster?
I am not a drone owner or user... but I just can't believe these things are that hazardous to an aircraft the size of a helicopter. Am I very very wrong here?
It's not the hazard, it's the potential hazard.
Let me set up the firefighting environment.
You're in an aircraft. Could be a helicopter. Could be an airplane (single engine agplanes are commonly used). You're flying low to the ground, because if you go too high, the effectiveness of your water/retardant/foam drop diminishes significantly. So you're having to fly in a narrow band of altitude above ground. You can't go up - lowers the effectiveness, you can't go down - reduces your spread, and again, lowers the effectiveness because you're not covering as wide an area.
OK, now we're near the fire. As everyone knows, heat rises, and fires generate a lot of it. This makes for wicked turbulence as you fly - it's extremely difficult maintaining attitude ("blue side up"). You've got to fly this path to lay your water/retardant/foam in the planned area, with air upsetting your aircraft and making it hard to keep a straight line (i.e., straight and level flight).
You're concentrating making your location, dropping your load (which alters the CG of your aircraft - in some, they will pitch up as they get lighter, in others, pitch down, and you must correct for this as you're dropping. If you don't, your chances of crashing are basically certain).
In other words, it's already a hard job, and now you want to add avoidance to the mix? I mean, if you're dropping, and a drone comes up, that could distract the pilot long enough to do the wrong thing. Or it could hit the aircraft and damage a prop, at a time when the workload is high.
I did mention you were already low to the ground, right? So if you have a problem, you can't fix it - and if you can't fix it, you're going down. If you're lucky, there's a crew nearby who will come to your aid in your crashed aircraft. If not, and you land in flames, well, hero down.
But I'm sure it was all worth it to be on YouTube, right?
And that's the real danger - it's really turbulent, so drones are no match for the wicked air currents. There's a chance that "harmless drone" far away could be gusted right into you, perhaps damaging a control surface (and it doesn't take much - the aluminum bends really easily).
Plus, it's high workload - you're already busy enough flying, you really shouldn't have to worry about other aircraft in the area. (And you don't - there's an aircraft flying overhead that manages the airspace so you will not encounter another firefighter accidentally. That control aircraft schedules every helicopter, agplane, waterbomber, etc., in sequence so as to allow the pilot to just concentrate on their job - dropping their load at the right place and right time).
Since this is /., how about a work analogy - say you have a deadline coming up and you need to finish your module by that time. In a normal environment, you're given the alone time you need to concentrate because it's tricky, and it's due end of the day. Drones are more like those coworkers and your boss asking you to come into a meeting, or bugging you every 10 minutes with a question. That's why drones are so dangerous - they're distracting and their potential for harm is heightened because of the urgency of the task at hand.
And in the end, really - it's all just so some idiot can have something cool to post on your YouTube channel.
And FYI - the airspace around a wildfire is restricted airspace - no aircraft allowed, including RC hobby aircraft, drones, etc., that are not authorized to be there. The FAA advisory circular is just that - advisory. It is not law, and anyone violating restricted airspace can be subject to criminal prosecution.
Hell, I'd enjoy if the insurance companies of those with burned up cars went after the drone pilots to recoup some of the damages.