A lot of people might have created Bitcoin wallets for fun (it takes just a few seconds). But these wallets are all empty, with no transaction ever occurring with them. I am afraid that the survey might have counted these wallets as well.
Most wallets do that automatically for convenience purposes. I however don't for a second think that they counted empty addresses because it's meaningless on its own as anyone can generate addresses out of thin air at any time. It would allow whales to easily manipulate the stats as it is practically free of any cost.
In these examples of "adoption", they count the addresses with an actual balance in them, and when the charts indicate growth, they directly assume it is related to more adoption, but that doesn't have to be the case at all. It's something surveys did years ago and still do it today. They are clueless when it comes to storage distribution, change addresses, etc.