I read what the naysayers above say, and can see where they're coming from.
However, I doubt that many PPLs (particularly those who like thinking hard about their flying, which is probably most on PPrune) will simply launch into a turnback into an emergency, when they've been trained to land "ahead". Not on the basis of what's been posted here.
On the other hand, it's already been demonstrated that some pilots as a result of reading this will go up to a safe altitude, and try flying a simulated turnback manoeuvre to understand and rehearse how it would work,and whether it's a good or stupid idea for them, flying their own aeroplane.
I cannot see any harm in that.
G