So if a woman decides to become and engineer, but she sucks at it. Worst engineer in the world. But she absolutely LOVES being an engineer and going to work everyday and it makes her happy and fulfilled, what's the problem with that?

If a man decides to be a stay at home dad, because he loves his kids and doesn't want to miss them growing up and lets his wife be the breadwinner, and everyone's happy, what's the problem with that?