Introducing laws requiring recycling and getting the laws to be obeyed are two different things. In the meantime, non-trivial amounts of WEEE (Waste Electrical and Electronic Equipment, aka electroscrap) are going to continue to be dumped in landfill or incinerated.
Heavy metal pollution is a very real problem which has been known about for some time. The restrictions on its use in electronics are recent, but restrictions on lead generally (e.g. paint, petrol) are hardly new.
Although the toxicity of lead (and other heavy metals) has been known about for some time, the risks of continuous exposure to relatively low levels (i.e. bioaccumulation) wasn't particularly well understood until quite recently.
Long-term, low-level exposure isn't something which can be easily simulated in laboratory tests. Also, while risks to specific sections of the population may be noticed due to increased incidence relative to the general population, that won't work for risks to the general population.
You are assuming that: a) the industry won't find any solution to the problem, and b) RoHS won't be modified in the event of a) occurring.
FWIW, I don't particularly blame the politicians for not simply accepting the industry's protestations at face value. Industry estimates of the costs and problems associated with mandatory changes frequently turn out to be overblown.