My frustration with Disney is that I was told three different things. I was told it was state law, company policy and then federal law so I wasn't sure what was true.
I can't believe some states card everyone. What's the rational for that? Clearly when you're in your 50s and 60s you don't look under 21?
Apparently you believe the law needs to be rational. You were misinformed.

To be fair to the CMs, they're not lawyers, they're guessing for a reason the customer will accept, they probably even believe it themselves.
Florida accepts the following ID:
- Any State Driver's License
- Military ID
- Passport or US Passport Card
- State-Issued ID Card
FL Stat. 562.11 Selling, giving, or serving alcoholic beverages to person under age 21; providing a proper name; misrepresenting or misstating age or age of another to induce licensee to serve alcoholic beverages to person under 21; penalties.—
(d) Any person charged with a violation of paragraph (a) has a complete defense if, at the time the alcoholic beverage was sold, given, served, or permitted to be served:
1. The buyer or recipient falsely evidenced that he or she was 21 years of age or older;
2. The appearance of the buyer or recipient was such that a prudent person would believe the buyer or recipient to be 21 years of age or older; and
3. Such person carefully checked a driver license or an identification card issued by this state or another state of the United States, a passport, or a United States Uniformed Services identification card presented by the buyer or recipient and acted in good faith and in reliance upon the representation and appearance of the buyer or recipient in the belief that the buyer or recipient was 21 years of age or older.
Notice that number 2 ends in "and," so it is stated in the conjunctive, not alternative.