Federal agencies do what they’re told.

The restrictions on pseudoephedrine were mandated by Congress through the Combat Methamphetamine Epidemic Act of 2005 (passed as part of the patriot act) which followed various state legislatures’ passages of similar laws.

The main driving force behind the law was Bush’s White House drug task force and several members of Congress.

Federal agencies very, very, rarely solicit or propose legislation like this. And Congress rarely asks for their input.

Did the FDA force drug manufacturers to replace pseudoephedrine with phenylephrine or did Congress make it more difficult to purchase pseudoephedrine and drug companies decided to make new products with phenylephrine to sell in addition to pseudoephedrine products?

Pharma companies decided to sell a drug that doesn’t work so they wouldn’t lose sales from pseudoephedrine going behind the counter. They could have simply chosen not to, alas. Also, that switch was required by law. It wasn’t at FDA’s discretion.

Why would that make you wonder about their intelligence?

FDA having different priorities than you is not the same as them being stupid.

I've never had a problem getting pseudoephedrine, though it is behind the counter in a pharmacy these days. There are limits, but they are well over what I would consider a therapeutic dose. I don't know if that varies state-to-state, but I doubt it's a federal issue.

pseudoephedrine is amazing, I just recently found it and unlike every other cold medicine I've ever tried it actually works and clears my nose.

US bureaucracy is the cafeteria for our unending food fights, pitting Profit Motive against Moral Panic.