No, they don't. Only when compared to men of the same height. Compared to men on the same standard curve for height, women have proportionally shorter legs.

That is, if the average height for a woman is 5'6", and the average height for a man is 5'11", the man will have an inseam proportionally longer than the woman's. A 5'6" man, on the other hand, will likely have an inseam proportionally shorter than the woman's. When men deviate from the mean, it's usually mostly because of differences in leg length, while women differ in torso length. Tall girls often have proportionally short legs, but since tall girls often also are thin girls, they look like they have longer legs.

In the case of the OP, 80 cm legs for 170 cm body is pretty much normal. I'm 179 cm with 85 cm inseam, which is proportionally longer.