Desdichado
Hero
I don't think there's any call to say someone's being dishonest because they say that the Realms is overdetailed and over-exposed. There's been plenty of honest dislike of the Realms online. If someone makes a more specific complaint, i.e., it's too detailed and that the sourcebooks are big fat spoilers for the players all the time, then why wouldn't you take them at their word?The whole idea that people couldn't run the Forgotten Realms because it had too much detail or lore is just a cop out. You're the DM. Run it like you want to. Besides, the Realms was big and diverse enough to find plenty of place to be your "sandbox" if that's want you wanted. Why can't people be honest, and just say they don't like the Realms instead of acting like their hands are tied by the "massive amount of FR lore" so they couldn't run it.? Talk about hyberbole.
I think your characterization is more of a cop-out. If the "well, you're the DM; ignore stuff that's published and do it your own way" is your solution, then why bother calling it the Realms at all? Just call it your homebrew and borrow any ideas from the Realms that you happen to like. And hope that your players aren't steeped in Realmsiana so they'll be spoilered once they recognize the obvious borrowings.