Frankly, it doesn't make a difference if the retirement age is
40 y.o. or 80 y.o..
1) If they set retirement age at 40 y.o., you don't have enough
savings, you still can't retire because we are not on a pension
system. 
2) Doesn't make a difference if the retirement age is 80 y.o.,
because with all the cheaper better faster and younger foreign
talents, we are still holding the shorter end of the
stick. Do you want to employ a young 20 y.o. who can do the job 2-3
times faster or an septuagenarian?
3) Basically the PAP policy is towards screwing the Singaporean
(but then again 66.6% of Singaporeans enjoyed being anal
penetrated), driving down wages (it's like trying to compete with
3rd world countries to see whose hand can reach the bottom of
the barrel first) so that they can remain competitive. Is
this the ONLY way to compete in the global market or do they lack
the initiative to figure out other ideas? Why is it that other
developed economies (Australia) have wages that are 5.5 times
higher than what a McDonalds' staff gets in Singapore? No
doubt they have higher taxes, but those higher taxes only affects
those in the higher income group. Though they tax alot from the
rich, they also provide other social benefits to their
citizens.