The point regarding misdirected spray is well heeded. It's one reason I considered the Kimberly product, since it directs the spray with a lot more force that is resistant to wind direction. Only has two "shots" though, so I thought the Sabre Red would be better since I can try it out to see how the spray actually comes out.
In any case, the issue is whether this is the best product to carry. I'd think it's certainly better to have something, as a last resort, than to be in the (yes, very rare) situation of having to protect your kids and not having anything beyond a loud voice and scared/adrenaline-pumping hands.
I'm not very concerned about bears since there have been no aggressive attacks, we're pretty much sticking to MUP's where we're unlikely to surprise a bear. Dogs have tended to be well-leashed too. So it's just a precaution, maybe I'm paranoid, but I'd rather have this thing strapped to my frame than not.