Very good fresh tofu is superb by itself, with just a splash of soy sauce and perhaps some fresh ginger or scallion. The same dish made from stale tofu, or even tofu that's just not much good, is mediocre or worse. It's a question of ingredient quality: if a given ingredient is excellent, it can be served very simply.
The problem, though, is that fresh tofu is not an easy thing to come by in the U.S. Just to give a strong example, I currently live in Kyoto, which pretty much everybody in Japan agrees is the best place for tofu. If you buy tofu in a package here, it has two dates: when it was made, and when it should be discarded. The difference is normally three days: if it's made on Monday, you should finish it up by Thursday at the latest. And if you're not going to cook it, you really should eat it by Tuesday. Any tofu that lasts longer than this has preservatives in it, and will have a mild to strong chemical taste. If you do have very fresh tofu, it must sit submerged in cold, clean, soft water, which should be changed at least daily.
The same rules apply to flavored tofu, which can be good if freshly made: yuzu tofu is fabulous on the day it's made, with just a dash of soy sauce. The problem isn't whether the tofu is or isn't flavored, it's whether it's worth eating, and if it has a long shelf life, which means it's full of preservatives, it's not worth eating.
Bottom line: Real tofu is to the usual packaged stuff as real cheese is to Velveeta. Would you make a big deal about your exciting new sandwich that uses 100% genuine Velveeta? Or would you only do that if you were using a good real cheese and wanted to draw attention to it? Same goes for tofu. If you want to attract and keep customers with these sandwiches, you must use really good tofu.