As someone who has spent decades having written conversations on the internet, it really seems like basic reading comprehension skills have plummeted recently. It's frustrating how many responses are replying to some objectively incorrect reading of what was written.
Here's the definition of "ostensibly"[1].
>in a way that appears or claims to be one thing when it is really something else
The correct reading of "ostensibly apolitical corporations" is "corporations that claim to be apolitical but in reality aren't". Not only is it not an indication of naïveté, it is closer to the exact opposite.
Agreed that it's generally intended to be condescending, but when the rest of the comment is reasonable I'll assume good faith; maybe the person has seen it used elsewhere and doesn't realize how it comes across. Or maybe they even know its condescending, but not that it undermines their other points. Either way I felt a bit of push-back couldn't hurt.