Rather than assuming that inanimate objects refuse to talk to me, I'd rather assume they're just objects
(edit: except if I have watched too many pixar movies
) But yeah, we don't know for sure.
My logic is based on the fact that basically all the sentient ones (of which we know are sentient for sure) we meet in our time, are either on display in the laboratory or are in our pocket... or...
are said pocket. Even if they might be well-known and not special, they are surely still rare. And especially in the player's case, where they are deliberately searching for the ones that are sentient, Dad doesn't seem to know what exactly they look like, so it's natural he would notice if his kid waltzed in with a shiny shield that blabbers every time you press A
And the shelved amnesiacs should be noticing that too.