Why Can't it Just be Labeled "Soap"?

I just went to quickly buy some shampoo, and I am continually frustrated by the fact that there seem to be millions of different products with names like "bathing cream" and the like that I fundamentally don't understand. Then when I look at the descriptions, I read how it's supposed to reduce my stress, make me relax, and so on. I don't see any descriptions about how it's supposed to make me clean, which is why I want to buy the bloody thing in the first place! There are just all these damn words I don't understand and with long, meaningless descriptions that don't explain anything ("full of sound and fury, signifying nothing"). I can't tell which product is which. Grrr. Why can't it just be labeled "soap"?