Difficult, this one. From the organisers point of view I should think the consequences of dropping the grouping rule could be disastrous. As Stolly points out, lots of people do it in the hope that they'll get grouped with folk who know the route. Those of us who live fairly locally always have to chance to recce the route, but those from further afield often don't.
I personally wouldn't mind going it alone, but I couldn't in all conscience leave a struggling fellow competitor to fend for themselves if it was obvious they needed a bit of help.
I think on balance I'd keep the grouping rule, I can see lots of calamities otherwise!