There's an easy fix for folks like yourself: most (all?) modern browsers support setting a minimum font size. Jack that up way into the double digits, and stop justifying ridiculously large font sizes for everyone.
> That would be a much better plan. See what I mean?
No, because there are cases where having large fonts makes sense (e.g. <h1> for article titles, etc) while preserving the ability to display smaller fonts than that (e.g. for article content).
Conversely, you could just ctrl-shift-plus and make the text as readable as you like, since it bothers you and stop justifying the rest of us having to jump through hoops.
Who should have to jump through hoops, the person who cannot read text that is too small, or the person who's sensibilities are offended by text that is too large?
Most operating systems have accessibility options to help with that. Consider helping your mother to use those, they exist for a reason. Punishing everyone just because a few folks need help is not the answer.
But flip the logic. Your inaccessible site, due to tiny unreadable fonts, is punishing everyone whose eyes aren't as good as yours, which is a lot of people.
Or just stick to the basic logic: you can increase tiny fonts, where as on most sites now I can't shrink them. So it is punishing.
Your mother is inconvenienced, we are punished. She only has to adjust one setting, where as I get no option.
And nobody is talking about tiny unreadable fonts, we're talking normal verses gigantic. If she can't read the normal OS font size, shes the problem and not the rest of us.