It's a great question without a simple answer. Some tobaccos, as with any other gustatory experience, present a single, more or less mono-dimensional flavour. They can be very enjoyable, but they don't tend to evolve throughout the bowl, nor do they offer a broadly fascinating taste experience.
Perhaps an analogy might illustrate. Simple monosaccharides, like fructose, the sugar that makes fruits sweet, are very simple tasting. They provide sweetness, and little more. Maple syrup, on the other hand, has a lot more going on in its overall flavour profile. The syrup would be considered more complex than the straight sugar.
Add the maple syrup to something else, perhaps using it in a glaze for a grilled pork tenderloin with coarse mustard, thyme, black pepper, salt. When combined with the umami from the meat, the caramelization from the grilling and so on, the result is significantly more complex than any of the ingredients alone. There are layers and layers of flavours and aromas to be revealed in the meat, only some of which can be easily traced back to the maple syrup.
Tobaccos are similar. Straight virginias have a relatively simple profile. Add Latakia, and the complexity is increased, but not dramatically so. Combine different virginias, latakia, orientals, press the leaf to enhance fermentation, then age the result for a while. Each individual component is still recognizable, but the whole is much more interesting than any of the parts alone. If done in such a way that the various elements combine harmoniously, you get complexity. The tobacco will show different sides of its personality with different pipes, different smoking techniques, even different environmental conditions, and the smoke will tend to evolve throughout the bowl.
There's a place for both. Sometimes, we crave something simple, easy, like a mass-market lager. Other times, we want something with depth, body, more engaging character, like a heavily dry-hopped IPA or a yeasty Belgian.
Does that help?
