“It is found (according to the paper linked above) in 261 different OTC products, and it is a useless bait-and-switch on the consumer in every one of them.”
Oral phenylephrine gets broken down in the gut before it can do much, with bioavailability that may be 1% or less. It replaced pseudoephedrine on open shelves because pseudoephedrine can be cooked into meth. Lowe notes the cartels now make meth cheaper and purer than any basement lab. Shoppers still buy a cold medicine that does nothing, and the drug companies still cash the checks.