Depends, for taxi drivers, it's a job that directly involves customer service, and many female clients may feel more safe riding alone if the driver is female. So if that's the problem they're hoping to solve by focusing on hiring female drivers then I don't think it's sexist.

But for construction and software, I don't see what this practice is trying to gain besides waving around the industry telling everyone they have diversity, when they're treating female employees as victory tokens instead of valued workers.

In general I feel the whole diversity practice recently is missing a huge point of the movement in the first place -- to not discriminate, and let everyone have a fair chance based on their abilities. How it has played out has just been discrimination in a different way. When companies do shit like this, minority groups feel their credits are being disregarded, and non-minority groups feel the other side have it easy by pulling a gender or race card, then they proceed to disregard minority group's ability when they're hired. Nobody is winning.

I've had more than one male friends that told me "You're a girl, you'll get hired even when you don't do so well at the interview", and who do you think are to blame?