The article presents no evidence that the complaints were due to the alleged implausibility of female engineers. In fact, I'd bet that many of the LinkedIn users who complained did so for feminist reasons—suspicious that the ads were using pictures of pretty women as a cynical ploy to increase clicks. So what we probably have here is a case of Group A's efforts to stamp out misogyny causing Group B to infer misogyny.
If I was in charge of Toptal's marketing department I would have responded with a new set of ads featuring shirtless Fabio lookalikes.