I think it is very easy for "experienced" pilots to forget some of the problems they had earlier in their "careers".
In theory new PPls can fly in pretty awful viz. however in reality the training is inadequate for them to do so. In theory after an IMC course you should manage an ILS let down to minima, however in reality you are unlikely to achieve a satisfactory performance.
It is commonly said PPLs are at their best just after having completed the course.
Not so.
Whilst it will vary from person to person I suspect on the whole the average PPLs skill levels gradually deteriorates after completing his course. If he continues to fly only in the local area, on good days, and, as many do, stops practising PFLs and cross wind landings and the host of other skill improvers, his skills will continue to deteriorate. In the end he will be unwilling to fly in anything other than excellent conditions or will give up - as so many do. However, some continue to stretch their horizons. These are the few that disprove the truism. Initially like everyone else their skill level deteriorates. Why - because they realise they are on their own, maybe scare themselves a few times, rightly are very wary of weather (because this was drummed into them during their training) and stop doing all the handling skills because it all seems a bit scarier without an instructor with them to save the day when things go wrong.
Sounds familiar?
These few disprove the truism because they realise if they are going to continue flying safely and more widely they need to hone their PPL skills. Somewhere around 200 and 400 hours they really start improving their skills again and will be far better pilots than they were when they finished their PPL.
Why does this happen?
As has been said on so many occasions before I think the anser is relatively simple. The PPL course is very good at wrapping the pilot in cotton wool. (And I am not saying that is wrong). However, the cotton wool is suddenly taken away - there is no support, no more experienced pilots to fly with, no reason to take on longer trips. Some pilots have sufficient self motivation to find another way. Some are fortunate in joining good groups or clubs early on. Most are not so fortunate or motivated.
In short, and as others have said, conditions of poor viz and “flying on top” are in my view not the conditions for a new PPL to go and enjoy. In my view the training is not good enough to deal with these conditions on your own. However, get some hours under your belt with more experienced pilots as soon as you can after your PPL - you will be amazed at how quickly your skill level will continue to improve IF you follow this course.