Why were these three factors not taken into account before we arrived at where we are now? They seem fairly obvious and could they not have been rectified some time ago ?
Are they obvious ? Given the size of the financial industry that relies on these figures it seems pretty unlikely that somebody wouldn't have noticed if it was. Remember the only way to measure life expectancy is to see when people die. That unfortunately tells you when that cohort died and until the end of the 80s was a pretty good guide to the next cohort but the figures suddenly shot up after that. There are a number of imponderables here. For example is some of this increased lifespan due to the fact that much of this cohort had quite an austere lifestyle at the start of their lives and if it is what will be the effect of the less austere beginning on the cohorts to come ? Remember also that a fair proportion of the fitter members of some recent cohorts never made it out of their twenties.
Investments should be wise with little risk attached.
But until very recently shares were giving high returns with seemingly little risk so why wouldn't you invest in them. If it was as obvious as you think how come so many people had shares in the banks when they went into freefall ? Now it is clear that shares aren't so risk free pension funds are moving to less risky investments but these have lower returns so the underlying rate goes up.