Is Prevention better than Cure?
If education and recurrent awareness and training is what 'prevention' offers - then Yes!
It is very helpful to students if the instructor is able to introduce them to deteriorating conditions of both forward visibility, and lowering cloud ceiling. Until a student can actually see for themselves what we are all talking about, and they can match the published VMC minima to what's in front of them - as instructors we are not helping to minimise this all too common way of becoming a statistic.
Forward visibility estimation is only possible where the distance between certain landmarks is already known, eg, 3nm, 5nm etc. GPS distance from a 'going to' location also helps with becoming familiar with what visibility is actually being seen. With cloud ceiling, it also helps if you actually have a good GPS with a reasonably accurate database to help with height above ground estimates, but this can also be done safely by simply using the altimeter and flying over a location of known height amsl in VMC.
The above only 'works' when you have a good VMC fallback position for 180 degrees of horizon, which allows for skirting of poor weather with clear cut escape direction. But, I have found it useful.
For what it's worth......