First of all, I want to make it clear that free speech is not threatened, whether we're PC or not. "Political correctness" is not a set of laws that dictate what you can and cannot say, it merely suggests that you shouldn't say certain things. Kind of like how your mother told you not to pick your nose in public — it's not illegal, it's just obnoxious.
That said, I think the biggest thing people miss with these kinds of discussions is the "meta" aspect of it. The ads in that quiz are funny not because we agree with them, but because we know they're stupid and outdated. When Daniel Tosh makes a black joke in front of a black audience it's not offensive. Why? Because it's being done ironically. He's making fun of the people who believe such nonsense, not espousing the belief himself. I think there's a lot of people don't get that irony.
I actually have to disagree. I believe free speech is threatened (and if it isn't, we should always be fighting to preserve, or expand it. Of course my opinion). I do not mean to say, that the random people on facebook saying Walmart distancing themselves from Redskins or blackface or anti-gays is "attacking free speech". That is free speech. In the same way Walmart doesn't sell giant dildos because they do not wish to offend, they may not sell {whatever the recent controversy}. That doesn't mean free speech is being attacked, but rather the bloc of people who agree with that position are big enough for Walmart to consider.
(Now, this goes along with the theory that businesses are entities {not people} that solely function to maximize profit, and minimize risk {to themselves}. If it's right or wrong, doesn't play into it so much as money. And image, public perception, etc, feed into that. The risk of backlash can be a big motivator.)
People (hicks) just get upset when they can't bully businesses into being good christian, faggot haters, and when they instead are dick loving hippies they get upset. Businesses are businesses. People project onto them. I digress.
I love your point about missing the "meta" discussion. If we can, I'd rather stray this conversation (and honestly most) that direction. Yes, the ads are funny. Not because I agree that women are made to cook, and I want my beer unburnt, but because it's funny. Why is it funny? Because of that model life (way of thinking) we know of (if we agree or not, in part or whole). The exaggeration is a part of it too. But it's not just funny because of "irony" (only). I do think things are funny because of irony, but there's more to it. Sometimes we do agree, even in a small way, with the things the images present. Mexicans are poor and hang sheets in their yard. ROFL. Are all mexicans dirty smelly poor white-trash bringing down my property values with their kids in my neighborhood? I don't need to answer that. Perhaps I do though.
I've done this plenty (and so far I've not gotten into too much trouble). But I'll say exaggerated things. Such as "girls are dumb" to invoke a response. Or to make people think. (Yes I will say it to girls. It can get dicey). I do not actually believe those things. Sometimes I'm being entirely ironic, because of whatever reason. Sometimes I'm exaggerating someone (a girl) being dumb. The point may be, I'm trying to contrast that something dumb a girl did is *not* because they are a girl. So if a women does something in the news, and someone says something causally to imply it's because they're a women, I then come out and explicity state what they were implying "all girls are dumb and stupid". Being confronted with an explicit statement like that makes people think. They may very well have said it innocently. I doubt they believe
all women are dumb and worthless creatures, but they might still be okay with the idea that girls are
generally dumber-not-smart-smart-fucktardsd compared to smart-smart-intelligent boys.