Actually Geni has built in user viewing preferences, so it’s important not to prevent others from applying their own view preferences.
https://www.geni.com/account_settings/name_preferences
Customize how names are displayed on Geni. These preferences apply to family trees, lists and the rest of Geni. Profiles always display the full name or display name. You may also change these settings in your tree, under the Preferences tab.
What I don't like is when people put a woman's name as both "married surname" and "birth surname" as the same. It makes it harder to locate someone on geni when it is done this way. If you want her "birth surname" to be displayed, just leave her "married surname" blank. Of course, some had the same married and birth surnames.
I would agree, it is very inaccurate for American women to have a last name same as birth surname before 1976, when the law was changed to allow a married woman to retain her birth surname: before then it was recorded as “surname” in vital Records. If a woman had a child out of wedlock, the child had her birth surname, not the father’s (even if known). So you can’t go wrong entering as the records show.