There's an interesting Q&A on this on the Vandersteen website (yes, Richard replies in all caps):
Alan (2/12/11): I have owned four pairs of Vandersteen loudspeakers over the past 21 years. If you could find a way to design your speakers with user removable/replaceable grill cloths, you would stand to be counted amongst the most enviable of men.
Answer: HELLO ALAN, THANK YOU FOR YOUR SUPPORT. I HAVE BEEN PUSHED, BEAT, BRIBED AND ABUSED ABOUT THIS FOR OVER 30 YEARS. I HAVE EVEN ENCOURAGED OTHERS TO TAKE THE CHALLENGE AND FIND SUCH A SOLUTION. EVERY IDEA INCLUDING MY OWN SERIOUSLY AFFECTED THE SOUND OR INCREASED THE PRICE APPROXIMATELY 100 PERCENT. IN THE END THE SOLUTION BECAME THE MODEL 5, QUATRO WOOD AND THE NEWLY ANNOUNCED TREO. THE QUATRO WOOD IS $10,700.00 A PAIR AND THE TREO (3A SIG SOUND BUT LESS BASS) $5990.00 PER PAIR BUT THEY ALL HAVE REMOVABLE GRILLES. SO FOR MANY YEARS WE HAVE THAT OPTION FOR THOSE WHO WANT TO PAY. THE NON REMOVABLE FABRIC WRAP IS WHY WE HAVE A 4 WAY SPEAKER WITH SCANSPEAK DRIVERS FOR $3950.00, NOBODY INCLUDING THE CHINESE CAN TOUCH THAT