TSMC to offer only one process at 20-nm Dylan McGrath
Based on market trends in high volume devices, it makes sense to have only one process targeting low power ARM based SOCs. This way you have smartphones, tablets and some PCs and cloud servers covered, a large enough market to feed into. Complexity in producing chips is increasing as the node progresses. Narrowing down your scope helps tame it somewhat.
I think he makes some interesting points on cost of production and how that influences choice of process. Blindly going after a higher resolution node doesn't make business sense (Moore's law is over-rated).
Because they think there's some money to be made in higher resolution chips and investing in ASML improves the chances of the equipment keeping pace with the demand. They could be wrong though. If the cost/wafer doesn't reduce as it has been in the past, they likely wont find many customers at the higher resolution. Intel's taken a risk in lining up so much fab capacity at the higher res nodes. They may get outpriced by lower resolution chips that have good enough performance.