Why so difficult? We used to race when the track was wet due to rain before the start of the race, even while the whole weekend was dry. Teams don't want to adjust their cars due to the diffusers and everything around it. The old wet tires used to be bigger so the ride height was adjusted by the tire size.
Yep, you've hit the nail on the head.
The way it is now, there's no risk in running too low because the race isn't ever going to go green if there's any standing water. But there is a risk to running too high, namely that it will dry out and any car running a higher than optimum ride height will be dog slow compared to the others, because extra ride height means throwing away downforce. So it's no surprise that the cars are all running too low to the ground, is it? There has to be a case for saying that, at some point, once everybody has had a chance to raise their ride height knowing what the conditions are, the race is just going to go green whether the teams have actually chosen to raise their ride heights or not. Then the penalty for running too low is that you'll crash.
This is very much analagous to what Davidson was saying about safer conditions leading to riskier driver behaviour. In the past, when the races used to go ahead almost regardless of the conditions, teams knew that if it was very wet they had no option but to run with enough ground clearance to avoid aquaplaning otherwise they would not finish the race. Now that the Race Director has decided he is not prepared to allow cars to crash even if it's their own fault for running too low, this just encourages reckless setup decisions, which have become standard.
The teams have the excuse, to some extent, that they are forced by the regulations to decide their setup in advance, without knowing for sure what the weather conditions will be, which is why I'm saying that when the weather changes for the worse, suspension adjustments should be permitted, or at least that the Race Director should have the option of allowing setup changes if he thinks that will help him safely to get the race underway in wet conditions. Some of the conditions F1 doesn't race in these days really ought to be fine.