There are a number of companies that can produce lithography machines, just not on the same level as ASML (at the moment anyway). Even if we ignore any patent/IP and upfront investment issues, designing and actually constructing machines which are on par with ASML's is not an easy task and will take years of research, assuming the project succeeds in the first place. What ASML is doing now is the culmination of years of research and investment and some pretty specific know-how. It's kind of like trying to replicate NASA's James Webb telescope project: many of the basic principles aren't very hard, but actually building the thing is.
I agree it's a tall order to compete with ASML, patents notwithstanding. So yes patents are not everything, even though cross-licensing is beneficial, rather than invent it yourself.
Actually the James Webb telescope, which has a scheduled launch this year, started out in 1996.
Given the 25 years it has taken so far and a huge amount of money, then it's not too far fetched to imagine someone replicating a space telescope.
