From a whiskey/whisky purists point of view. It's a bit of a a no-no for two main reasons.

Firstly, it's not traditional. Ireland and Scotland have made this drink for a really long time - long before the invention of refrigeration. There are people who say you should adhere to the old ways. It's no different to Champagne not being served overly chilled. Which brings us on to the second reason, the taste. You can taste more subtleties in the flavour of a good whiskey/whisky when it's not ice cold/chilled. In Ireland and the UK if you're buying a good whiskey in a bar they should ask you how you want it. The traditional way is with a very small jug of water on the side. Some dilution will help the flavour of the whiskey, especially if it's a stronger cask strength single malt. Just a splash mind, just enough to see the mixing of the two liquids on the surface of the drink in your glass. It releases more of an 'expression' of the drink.

Of course, that's over here. In the States there's an incredibly rich history of cocktails and the like and, more generally, a longstanding culture of having ice in your drinks. Why? because your climate's warmer which really is a maybe a third reason - its colder here. If it's 90 degrees outside i think i'd take a couple of rocks, or maybe still take it straight and have a tall glass of chilled water on the side.

But whatever, there's no real right or wrong. If you like it that way, drink it that way. And there are good counter arguments to be made, it sounds nicer as you pour some whiskey over ice and it cracks and then the relaxing clinking sound as you swirl them around in the glass. It definitely adds something.