FFF - you are quite right, but since when was this new fangled thing called the INTERNET a part of PPL syllabus?
A
PROB needs to be supplemented by radar or similar data but only if people know about it. The availability is only a recent development -
Meteox has been around only a year or two.
And, once outside one's home or club environment, how many airfields have a public PC with internet on it? Mine certainly doesn't. And the vast majority of pilots have no mobile internet and therefore no means of getting supporting info on weather once away from home.
I doubt anybody saying the forecast is duff will be able to support it with data - not because they are wrong but because getting the evidence (other than one for one's local area) is never easy. And anytime there is a PROB in there, you are wasting your time totally.