Spray works in calm conditions and when the range is very short. Obviously the bear cannot hurt you unless it can touch you, but if a bear gets within spray range (10') I want to be able to kill it.
I'd love to kill it too, there's no doubt. But lets face it - if a bear gets within 10 feet your chances of readying your firearm and bringing it to bear on the bear (

) AND getting an accurate shot off is not great. Spray has the advantage of being able to be fired from within the holster without removing it and at those close ranges doesn't even need to be aimed much.
I'd rather use my spray and force the bear to break off - and then shoot it before it gets its whits about it. That's a much easier kill that trying to get a good round off at a charging shape with no real time to aim while it's at your feet.
If i SAW the bear before hand and had time to get ready, that's different. but the bear would never make it within 10 feet. However often attacks happen suddenly and with no warning.
When the bear is that close and you choose spray, you have already discounted the use of a firearm, either because you don't have one with you, or because you are of the belief that you don't need to kill the bear.
At 10 feet? I think there's another reason you've discounted the gun - there is no time unless you happen to be lucky enough to have it in your hands already. To be honest if the bear is charging at 10 feet i doubt there's enough time for the spray, but you've got a much better chance.
But lets say it breaks cover at 15 -20 yards and you notice it. By the time you can react at all, it's likely closed to under 10 yards. At that point if you happen to be one of the lucky few who is allowed to carry a pistol, you MIGHT get off a shot if you've got it in a holster and you've practiced a hell of a lot. But i don't care who you are - getting a rifle or shotgun off your shoulder, arming it, and aiming and hitting the bear in the time you've got is just not going to happen, you're talking about less than a second, and that's if you didn't 'freeze' at all. The best you can hope for really is that the noise and blast will cause the bear to break off (which does happen) and that's if you even get a round off at all. But spray fired from the hip inside the holster IS a viable option and stands a good chance of breaking the charge.
once the charge is broken, you have time to ready your gun and shoot the bear.
And at ten yards or less fired in a line with the bear (and not pointed like a pistol) the spray will work just fine even under very windy conditions.
If you stumbled onto the bear in heavy cover, whether you like it or not, it's up to him what happens next.
That's probably true - tho again your chances of getting to your spray and using it are better than a gun. You can just hose down the brush in the direction you think the bear is in and stand a good chance of discouraging the bear for a short time.
If you are in a remote area and you get bear spray in your eyes you are in serious trouble, never mind the bear.
It's really not that bad - if you get a blast full in the face you're going to be pretty f-ed up for an hour or so. But most of the time you're talking about a light misting that's blown in your face by the wind or something, and while it's painful it's not disabling.
Word of advice tho - DO NOT TOUCH YOUR FACE WITH YOUR HAND
Noise makers are a better companion to a gun than spray. The noise makers could be pyrotechnic or canned air horns, although I prefer something that can project a scare device at the bear.
Virtually all bear experts agree that is not true. Air horns CAN be highly useful in announcing your presence and scaring off bears before an encounter - but once the bear is in sight and is hostile, as you mention what they've found is that there's a good chance that your noisemaker will scare the bear right towards you. They are more useful in chasing off a non-hostile bear that's poking around where it shoulnd't be - and shouldn't be used without a firearm or at least spray as a back up.
The fact is - bear spray has worked and worked very well in literally hundreds of cases. That's too many to dispute - it works. Period. Nobody in those situations is ever 'disabled', tho some are in pain if they get a little in their eyes. (but less pain than being eaten

)
The problem with spray is, as you mention, the range has to be very short (compared to a gun). The 30 feet that most manufacturers suggest is slightly optimistic, and more like 20 - 25 feet is realistic. So you have to have big brass ones and hold your fire until then or you'll use up your spray before the bear is even in range.
Also - with sprays it's been noted that bears (black bears in particular) will often re-attack a short time later. YOu could easily run out of spray before you run out of bear.
But - it's very easy to have with you, you never need to put it down, it is FAST - at LEAST as fast as a pistol, and it does not need to be aimed much. That gives it a huge edge over a rifle/shotgun in some circumstances. It's also legal pretty much everywhere. Even in the city, so if you're at a local park where there's bears (which is often the case in bc) you can still carry it. You can also hose down a bear even if it's already got ahold of someone in your party.
Spray is also much much cheaper and easier to teach people to use - so it's easier to arm everyone in your party, even those who've never used a gun before.
Guns are obviously longer range, and very effective. But - the are heavier, they often need to be put down while you do something, and they are slower unless you know the bear is out there and have readied in advance. (often not the case). They have the advantage of settling the dispute permanently tho
Which brings me back to my original statement. Bear spray works. We KNOW that. Anyone who says different either doesn't know how to use it or is kidding themselves - there's WAY too many actual uses to argue differently. But it has some nasty limitations. And it's no guarantee of safety.
Longguns are effective too - but they have limits too, and are often not a viable option in a specific circumstance. Lots of people have been killed by a bear while holding a gun. A lot more have been killed with their gun leaning against a tree or still back on the atv well out of reach.
If you understand both well and what each can and cannot do, you can mix and match your tools to your circumstances and have much better 'coverage' in a wider range of circumstances.