Wilson was the one who forced the £1 to be the basis of the "new currency" just so that he could say "This doesn't mean that the pound in your pocket will be worth less".
A great many people argued for the shilling to be the basic unit but some felt it was "Too Austrian" ... I recall that some went so far as to suggest it smacked of Hitler.

The fear Wilson had was that an item previously costing a pound would be perceived as having doubled in price because the "New Pound" would in fact be worth half what the old one had been as the item price ticket would change from £1 to £2. Personally I don't think that many would have been so stupid but that was his thinking.