Might be true for the vast majority of whisky, but once you start to hit enthusiast territory, there's whisky from 40% to above 60% ABV. Some of those (including but not limited to "cask strength" bottlings) are certainly made for diluting further. Or rather, to give the customer the option to dilute to taste.
> Before bottling, the whisky is diluted to around 40 vol-% by the addition of water, which changes the taste significantly. Whisky enthusiasts often also add a few drops of water to the spirit before drinking in order to further enhance the taste.
I'd say that's simply not true, at least for my "enthusiast" circles. 40% whiskies are becoming increasingly rare in those groups.