Some people on the internet and forums have said that they believe retrohaling to be unnecessary, but I can't see at all how one could taste anything except ash and smoke without retrohaling.
The only flavors we can taste on the tongue is: sweet, salty, sour, bitter, and umami. All other aromas come from exhaling through the nose. So when you can't taste anything because you have congestion, it's probably because you can't exhale from your nose. I don't see how smoking a pipe is much different?
I don't mean to bash on anyone here, at all, I am just wondering what you all think?
From a purely physiological sense, you're correct. Our perception of flavor comes from a combination of sensors in our mouth and our nose. No mystery about that.
However, any number of other factors can affect how we perceive or fail to perceive flavors, environmental factors, for example.
If you're an indoor smoker you're inhaling and smelling the smoke by virtue of being in an enclosed space filled with it. Snorking may still offer some benefit, but likely you're already getting the other flavor nuances through breathing it in. If you're an outdoor only smoker you don't have that benefit so snorking is the next best thing for picking up nuances.
Age is another factor. As we age, our senses can become less acute, including out sense of taste and smell, which combine to give us our perception of flavor.
And there's the reality that not everyone is born with an equal capacity to sense flavors, or that our capacity has severely declined for one of several reasons. Our ability to benefit from a snork is limited because our ability to perceive olfactory imput is limited.
Since I'm an outdoors only smoker with still strong senses, snorking really adds dimension to the flavors to be found in the smoke. For others, for the reasons stated above, it may not.