AP, clearly you are a regular user of the airport and seem fully conversant with the procedures there.
Just imagine that you are not, you are a european or non european pliot whose first language is not English, you are cleared to holding point "x" when suddenly you see "runway ahead", signs then a Cat 1/2 or 3 holding point, of course you've read the notams and noticed that 30 is closed today but that was an hour or so ago, its busy on the flight deck cos you're preparing for departure and your colleague can't remember either, what would you do?
Sail blithely across the runway or stop until the clearance is crystal clear? I would hope that its the latter.
I can understand your frustration and that of the ATCOs who have to implement the procedure, but any runway crossing requires a positive clearance for the reasons already given and the above.