I have never seen the point of starting people on .22s.
If you happen to like .22s, I have nothing against them. I think they are potentially a useful training tool if you understand their limitations...my preference is for a conversion kit for an existing firearm so the trigger is exactly the same as on your real gun.
I have an AA kit for my G17, for example.
But I don't have a ton of use for .22 pistols generally. I find them a little boring to shoot, and if you spend all your time on .22s, you don't learn to manage recoil properly.
Of course you can get pretty good on trigger press, and sight alignment, and all that...but that's all pretty easy anyway. I have generally had the experience that most people, in the space of an afternoon, can learn to slow-fire very tight groups with a bit of instruction. It's recoil management that seems to be the sticking point for most shooters I see.