Otherwise she will just ask for "Mucinex" because it worked really well that one time. This ignores the fact that like all of the *Quils, Sudafeds, Tylenol Cold-Flu-and-Explosive-Diarrheas, and Robitussins, there are multiple preparations made from various ingredients.
If I need an expectorant, I want guaifenesin. Cough suppressant: dextromethorphan. Decongestant: psuedoephedrine. Pain reliever: acetaminophen or ibuprofen or whatever.
It also doesn't help that it's hard to find the specific mix you need in a single preparation but it's also gotten harder to find just single ingredient store brands of some of these as well.
I don't want to take something I don't need so I'd rather not just buy some name brand kitchen-sink capsule that adds various decongestants or antihistamines if I don't need them.
But then the same focus on brand names and basic descriptions can lead to people buying homeopathic sugar pills because they're in the same department and list similar symptoms. If you never shop by ingredient, you won't know that a 1000x diluted extract of duck liver isn't the same as pseudoephedrine and guaifenesin.