Here's a relevant question:

Were they hiring any male waitstaff to serve beverages? Or any women waitstaff over 40, for example?

I'm pretty sure they weren't doing either of those things.

Which makes it more than just a PR flub.

About overreactions -- well... these problems are so pervasive, and ignorance is so persistent, and under-reaction is so easily brushed aside, that it's very well worth it to make some noise.

Some people (not most) will change their behavior because they actually understand the problem and realize they're part of the cause. Other people are going to change their behavior because the femi-nazis will start a witch-hunt otherwise (damn, there seem to be more and more of them around!), and will feel that way about it until the day they die.

Either way: better than no change in behavior.

I agree that there is less forethought or less "malice" in this advertisement versus one that outright lists women as a perk, but again, this is hard to continue to repeat everywhere. You see an ad, it's the 20th ad you've seen this week that reminds you that you're a commodity. You're eye-candy used to move a product for horny men who, apparently, buy with the brain in their pants instead of the one in their head. It plays into sexism that is not just anti-women but anti-men in my opinion.