Oh, come on. My unabridged dictionary gives "little" and "tiny" as synonyms of each other. I don't see any substantial difference in interpreting
Annette as "little
Anne" vs. "tiny
Anne". I suppose that to most native English speakers, "tiny" sounds like "very little", but does that mean that in order to use "tiny" you have to be talking about a name that's a "double diminutive" like Annetty?
Yes, it's inaccurate, but it's clear how the "inaccuracy" evolved through a reasonable misinterpretation.
Very few of the people who put up baby name sites are creating their inaccurate name origins out of whole cloth. Most of the ones you see were in print in baby name books 50 years ago. Their problem is in uncritically accepting as the full truth the first written information they come across. And understanding that that isn't how one does proper research is a skill that's developed over time. No one becomes an expert in any field overnight.