@stuck in the 50's... the 60's... the 70's... the 80's....the 90's .... the end was close too. Question is was it wise of them to purchase and build a lot of stuff during those decades or not?
What would have happened if they would not have build anything 'because the end was so close' ?
So from their perspective it's very logical to keep on building, even when the end is so close simply because a few decades wont make a real difference if you look at 6000 years of biblical human history if the end comes now or in 75 years its still close on that timescale.