I'm playing devil's advocate here.
You have to look at Airsoft from the general public's point of view and the reality of how firearms and firearm related items are viewed here in Canada.
The simple fact is even though we consider these things toys, they are 1:1 scale replicas of the real deal. They look and feel like real guns and as such, they should be treated like real guns.
If you haul one out in public, neither joe public nor the authorities are going to see a toy, they are going to see a gun and perceive the threat as real.
Put yourself in the shoes of the LEO.
You respond to a call, only to come upon a person holding a handgun. The person aims the handgun at you or someone else. What will you do? Will you ponder whether or not the gun is a airsoft or a real gun? No, you will see a real gun and treat it as a real threat to you life.
The "airsoft is a toy" excuse just doesn't cut it.
Adding Airsoft guns to the PAL might help to stem SOME of the morons from doing this sort of thing, but other characters, and those with less than honouorable intentions, will just look for alternative ways of getting them (getting them from the US or other illegal ways. We all know it can be done and has been done.)
Therefore, adding them to the PAL would not solve that problem.
IMO, the Canadian Government would not be willing to spend countless dollars and resources, to classify Airsoft guns on a PAL when these items are already pretty much deemed prohibited anyways (yes, I know there is a grey area here regarding where Airsoft guns fall.)
At any rate, if there were classed as non prohibited devices, I see the government just amending the law to include them as prohibited devices, instead of spending the time, money, and effort to add them to the CFC database.
Let's face it, in the eyes of the government, they have enough to deal with the registration of real firearms. Do you think they would be willing to spend their precious resources on classifying Airsoft guns on a PAL too?