So sad. But LOC in IMC is a tragically familiar scenario - and of course it's only a question of time before the next one happens.
Helinut is right here, some pilots are just too reluctant to put the thing down whilst visibility is good enough - and frankly it can be pretty poor to achieve this safely. I frequently wonder how inexperienced pilots can get into this situation - do they just not appreciate how bad the vis is and simply stumble into IMC at presumably low level, or are they knowingly taking huge risks pushing on, groping through the murk and trying to dodge around the lowest cloud and mist? The right approach is simple - fly lower and slower in order to maintain good ground reference until you need to land or turn back, possibly trying another lower route if it exists.
Pilots certainly need to be ready to land as soon as concern and doubt hits them - decision making will deteriorate rapidly from this point. Maybe training should include a number of simulated bad weather landings using pre-arranged farmers' fields known to the flying school? Agree with CF that IMC training is of limited benefit. If you get IMC when you should be VMC you are likely to be very low in mist and the chance of maintaining height accurately enough through a 180 deg turn on instruments to avoid hitting the ground is negligable. The 180 turn must be done earlier when still in albeit maybe poor VMC, and then to the right (assuming flying from RHS) and pilots trained to turn this way and get used to clinging to ground reference, even through the door window, because their lives DO depend on it. Teaching low level, tight turns like this would be more beneficial than turns on instruments in IMC, I feel.
The best instrument escape from inadvertent IMC entry at low level on flatish terrain is likely be a wings level steep climb to MSA and sort it out from there, but that's a whole different ball game and unlikely to be survived either by a non IR pilot.
But as has been said before, it's atttude that's the biggest issue and killer. Most of us fly in poor VMC weather from time to time and a very high level of judgement is required. Perhaps the best thing that should happen is that all students should have to read at least 10 LOC in IMC AAIB reports and maybe have detailed cause identication as an exam subject.