.22s have their place. For young shooters they offer a properly sized weapon and recoil.
They also (used to) be a very inexpensive round to plink with, and offer their own challenges.
They can be used for extremely compact carry, which many people won't prefer, but in some cases is better than no carry.
Now I wouldn't choose one to carry, personally, but I'd entertain the idea of having one to take to the range for some cheap pinking, maybe once .22 ammo is readily available again.
I know my 15 yo daughter really enjoyed shooting my dad's old Ruger Super Blackhawk. She's smaller sized and the long barrel was difficult for her. I think she would really get a kick out of a more properly sized and balanced .22.
I agree, shooting for fun is a different deal, and for cost and other reasons why not?
But for self-defense, no. Granted, a .22 is better than nothing, but so is a brick.
What follows is a teaching opinion, but it's one I think is reasonably well-grounded: when I see people want to start new shooters on .22 pistols, I just cringe. They think they're doing the new shooter a favor but in reality, IMO, they're teaching them to be afraid of recoil.
[I know sometimes this is to teach trigger control, but I think it can work as cross-purposes. I teach trigger control two ways: empty gun (double-check), balance a 9mm casing on the front sight, have them pull the trigger. When they can do that, proper grip and smooth trigger release, they have trigger control. No rounds expended, and it works. ]
With a proper grip, recoil in anything .45ACP or lower is more than manageable. When I teach new shooters who have never shot a gun, I start them on 9mm. I teach them proper grip, and when they're holding an empty gun (checked twice), I have them take a grip and try to pull the gun from their hand to show how hard they should be gripping it.
I have them watch me shoot 1-3 rounds, and I tell them to focus on the gun, not the target: watch what it does. It comes right back down after the muzzle flip, doesn't it? So if you have a good grip, recoil is managed.
I tell them recoil is something to be embraced and enjoyed; if the gun didn't move, neither would the bullet, and we should be focused on the target anyway, not the gun. Recoil is part of the fun, and if you are well-grounded in fundamentals, recoil won't matter to you.
IMO, people who want to "ease" shooters into this with a low-recoil .22 are telling the shooter that the other guns are harder to shoot, that recoil is an issue--it's all a lot of negative karma, IMO.
When I introduce new shooters to pistols, I have them load one round, and we place the target about 3 yards away. I want that first round on paper, so they can see the results of what they just did. I usually also take down that first target with one hole in it, so they can keep it.
And most often, that first round is right at or very close to the bullseye. That in itself is a very nice confidence booster, along with me praising their grip, aiming, whatever.
Nothing against .22s in a small rifle, or even in a pistol--but IMO, using that as a beginning gun is using it as a crutch.
My 2 cents, YMMV, everyone's entitled to their opinion, and I respect yours even if I don't fully agree with it.