They don’t have a legitimate complaint in any legal sense, and I agree that their getting too upset about a “silly” commercial may do them more harm than good…
At the same time, I think in the social sense, everyone has a legitimate complaint when they feel some issue is being made light of or otherwise poorly treated.
An article I found on U. S. News makes me think this was less about the Doritos commercial specifically, and more a point NARAL was trying to make about how often media, and especially commercials, play into stereotypes (particularly sexist ones). I suspect, that since NARAL tweeted about so many commercials, they were trying to show how pervasive this kind of stereotypical thinking is… Perhaps if we try to critique any one media portrayal of gendered stereotypes, or brusque treatment of sensitive social issues, it can look a bit frivolous… But demonstrating how widespread the pattern of “tiny” sexist digs actually is can help us better appreciate the larger social effects of those accumulating tidbits.
Anyway, if we were to critique one commercial itself:
Part of NARAL’s complaint about the Doritos commercial was the “sexist tropes of dads as clueless and moms as uptight.” And wasn’t it the dynamic between the parents that made it “funny”? The commercial doesn’t start with the fetus, but with the wife’s annoyance that her husband was eating Doritos at the ultrasound. And as he begins to notice the fetus’s reactions, she’s telling the doctor “see what I have to deal with?” The wife only gets mad after the husband makes the baby jump up against her stomach, effectively head-butting her from the inside—which seems like a fair response, but is still treated humorously. She says “ow” and he laughs…. And we have the stereotypical “clueless” man and “uptight” woman. The fetus just seems to be a mechanism for amplifying the situation, so that we can get some outrageous outcome (sudden labor) from a “believable” bickering duo. Conceptually, we were supposed to laugh at how events unfolded between the dad’s fooling around, and the mom’s trying to get him to stop, and then laugh at how the whole situation devolves. The fetus itself might have been surprising, but it wouldn’t have been funny. Would it have been as funny if the dad stopped? If the mom had joined in on the humor, and placed the chip on her stomach? Etc. The humor was in the “sexist tropes.”
I’ve heard people argue that making humor out of stereotypes can help to dismantle them. I have a hard time with that concept, so I generally don’t find that kind of humor funny. However, whether someone considers the commercial light silly and harmless, with no significant social impact, or whether they consider it socially harmful, reinforcing stereotypes, or whether they consider it socially beneficial, deconstructing the stereotypes, it seems NARAL’s at least somewhat accurate in their critique: it relies on sexist concepts.