Do you know why videos were so popular and had so much success and why VHS beat betamax?
Do you know why the internet developed so quickly and why broadband was taken up much more quickly than industry expectations and technological change would otherwise have predicted?
The fact that female robots are being developed is a clue to the above.
VHS was cheaper than beatmax and this made up for the lack of quality over betamax. It allowed for the production and distribution of cheap mass market porn.
Broadband took over that market. Porn on dialup just wasn't doing the business.
Technological change follows patterns of demand. The demand for cheap easily accessible porn was huge and the money it generated was enormous and drove video and the internet.
NOW ask yourself, why female robots?