Heres the spiel:
The first thing to know is that traditionally whiskey was alway drunk watered. “Proper” service outside the US involved serving the whiskey with a pitcher of very, very cold water for people to water to taste. I’m working from memory, but IIRC this was until the late 19th century and persisted in Ireland into the 20th. The American habit of drinking whiskey neat, and as shots, was one of many ways in which Americans were rough and backwards.
Now that was before it was normal to package whiskey at 80 proof, prewatered. But theres no indication that 80 proof was the “correct” level of dilution. As the drinker added water to taste. And whiskey and water is still a cocktail, though largely displaced by whiskey and soda. Which is a really nice cocktail, especially if you toss some port or aperal in there, that involves heavy dilution of whiskey.
In terms of whiskey on the rocks. Whiskey (and other aged distilled beverages) is really complex. There are compounds in there that you can’t taste or smell at certain dilutions and temperatures. Some of them aren’t accessible unless you warm it up a bit (which is why some people use snifters). Some of them aren’t accessible unless you chill it down. Different flavors receed and come out at different temperatures as you head downwards. And the same with dilution level. The alcohol burn of neat whiskey, especially over proof whiskey can blow out your pallat preventing you from tasting even the flavors that exist at room temp.
What happens when you drink whiskey on the rocks is you move through those things in stages. The first sip is effectively full strength, at room temp. But with the alcohol bite softened. As the ice melts, and the temp heads down. Different flavors come in and out, the whiskey develops, the full flavor comes out, it continues to soften, subtler flavors become noticable. Then those subtle flavors drop off and the whiskey’s dominant notes take over. Until its fully to over diluted. And all thats left is whatever its dominant character is. Its a process and its dynamic.
That’s why people drink whiskey with a specific number of cubes or amount of water. They’re trying to stall things out at their prefered part of the process.
The no ice in anything crowd also forget two key things. First alcohol gets you drunk and adding ice is a great way to slow that down. Second, a lot of what we drink doesnt actually have all that complex awesomeness that supposedly warrents kid gloves.
So for every day drinking the ice doesnt matter, and helps you pace yourself.
And for “special” whiskey you’ll learn more about that whiskey, more granularly, drinking it with some ice. You’ll train your pallat to pick out individual flavors. You’ll notice things about the whiskey you might never have noticed otherwise.
It doesnt have to be your thing. But if you give a shit about whiskey, rather than just trying to signal something. You should make it a point to drink your whiskey on the rocks from time to time. Just like you should make it a point to drink your whiksey neat. Slightly watered. In a snifter. And in cocktails. Otherwise you don’t understand the subject fully.
Anything else is just personal preference.