I think people have a habit of assuming men did the real work in a project, so they get a disproportionate share of the credit. People also have a habit of pushing women towards front end work, making the assumption that men are more 'technical' than women. It can be difficult to watch men get all of the credit for your blood, sweat and tears. It's especially bitter when they then say it's a meritocracy and you feel like saying 'what exactly did you contribute to this?'.
The concept of a meritocracy sounds nice on paper, but I think it ignores how humans work. The first issue is that I don't think we are especially good at identifying the best unless it's very easy to measure (sport for example). The second point is that it takes work to overcome your own biases and I think this feeds into how we evaluate 'the best' more than we like to admit.