Not so. I know a lot of people including myself who haven't had access to Wi-Fi.
And despite you not realizing it/preferring to ignore it, you and those whom you claim to know are in the minority. Not only is Wi-Fi tremendously prevalent in this day and age, but getting it in your home is about as hard as spending $50 on a good wireless router and setting it up. Now, if that manner of expenditure isn't feasible for you for whatever reason, fine, but that doesn't mean the technology isn't readily available.
In fact, everytime there's an event via Wi-Fi, the threads dedicated to the event itself are swamped with people complaining about not being able to download it so I know it gets messy.
And in such an occasion, which dogs are going to bark the loudest? The ones who are having problems, or the ones who were able to download the event completely without issue?
For every person who claims to be having a problem, at least half of which I'd wager could be self-diagnosed and fixed with a few drops of common sense and/or changing the router settings, there are at least two who have no issues and don't feel the need to post to announce as much.
Unless you have a graph or some sort of actual statistics as to how many people have Wi-Fi and how many don't, I wouldn't assume much :|
This isn't an argument. You can go to any number of resources and find any manner of statistics stating how many individuals say they have access to Wi-Fi in North America, and even if you choose to ignore those facts, that Nintendo of America continues to use Wi-Fi as a distribution method when they aren't trying to push merchandise alongside an event Pokémon tells you every bit of what you need to know.
Events that were movie-related in Japan will almost certainly continue to be in-store in America. Other than that, all bets are off as to what will eventually be Wi-Fi bound.