You know what, I think all this supply/demand problem is down to VW UK and its dealer network.
I mean, the German factory will be happy to bang out as many cars as people will buy, as they will make a profit on every unit (more so for a higher output with economies of scale).
But VW UK stand to profit more from a restricted supply because of the way we buy cars - they earn an income from the first owner (or two) and by keeping the residuals up earn more when they do finally sell it out of the dealer network. High residuals seem to help us as first owners, but in fact keeps just helps VW UK line their pockets.
I can imagine this is even more important these days on the GTI/GTD/R as they are loaded with extras which would have been expensive options only a few years ago - got to fund those somehow.
I don't like VW UK - I've bought several of my previous VW's in UK spec from European dealers but don't seem to be able to any more.