"Census records, birth records, and most death records are "matched" with birth dates, for a start"
True, but they can also be matched on other criteria. Nor are you required to enter a date of birth when you search; it merely helps you narrow the results. If I get one William Smith in Missouri, and another in Oregon, or one born in 1784, and another in 1901, it's usually pretty easy to pick the more interesting one out of the list. And if I do wish to enter an estimated DOB, I can do that at the time I do my search; I don't really need to put it in my database.
"As for the rest, I've heard all of the arguments from folks who don't estimate their birth dates and they don't wash with me."
Well, I'm not trying to convince you of anything; I'm only explaining my own predilections. How you do your research, and what you put in your database is, of course, your own decision entirely. But I didn't say I don't estimate birth dates, only that I don't enter them as facts in my database because they're not facts, and I prefer to keep my facts and conclusions separate.
So yes, I understand what you're saying. It just doesn't fit my style.