I love to agree with you but there is one little detail:
Without demand, there will not be jobs.
No jobs, there is no demand.
It's a vicious cycle.
That said, space exploration might create a ton of jobs in all fields but since this is not a guarantee and in the short term cost a lot of money, governments rather invest in waging war due to the short term money it produces for them (oil etc.).
Politicians are only concerned with their terms as politicians. When they made the money, they leave and another one fills the spot with their own agenda.
I get this feeling that the politician as public servant doesn't really exist anymore.
In the last few decades, were there any politicians of importance in the western world with a longterm vision? Please name them so they can duly be credited.