The current lithography machines use 193 nm light, and for the past 10 years we've been waiting for extreme ultraviolet machines, that emit 13.5nm light.
It's pretty obvious that the this challange is far greater than anticipated — ASML was talking about shipping it in 2010 (!).
So why take such a huge leap? We're talking order-of-magnitude jump in wavelength. Why not go to 100nm light first? Or 50nm? Wouldn't it be easier to develop this EUV technology more iteratively and gradually improve and fix all the problems (light source, power, availability, pellicles, mirrors, etc.) one by one as they arise when stepping between wavelengths?