I think the main point is rimfire should be disqualified for self defense because its rimfire, automatically. 25 ACP vs. 22lr is settled by the point one is inherently far more reliable because its centerfire. 22 magnum vs. 32 ACP? Well, one is centerfire and more reliable. Cheap affordable pistol caliber carbines are available that even weak people of limited physical capacity can use comfortably and train with. A full barrel 410 shotgun is easy to handle, often cheap, far more effective shot for shot, and again not rimfire. If you are going to chime in on rifles and full carbines, that an AR15 in 5.56 NATO is mild enough for young, elderly, crippled, than here we are again, better killing and not rimfire.
I train with 22lr, shoot 10 rounds of rifle and 10 round through my PPK/s every day. Despite being good with that Walther I still don't consider it a self defense gun, just a trainer. Good way to keep proficiency, good to train and plink, not really good enough for self defense. It has its place, and its place is not there.
If our hollow point causes one hangup in 200 rounds in our auto loader, the whole incident might keep us up at night, we'll always remember the time it jammed us. Yet when a rimfire fails once every 200 rounds we just laugh it off and "oh, that's just rimfire" because its our old, cheap friend. Why is it OK with one and not the other, in terms of critical emergency combat use? Its not merely terminal performance I'm concerned with in 22lr or 22 magnum, its the rimfire issue first and foremost.