It's easy to get pseudoephedrine here (but harder to get straight-up ephedrine), but you can't buy the entire store's stock. The only formulation that is behind the shelf is when it is the only drug in the pill. That's probably for the better. But in mix formulations like in most sinus medications, they're on shelf like everything else.
In my household, we use pseudoephedrine when our symptoms become unbearable, because it dries out the nasal passages so well that sometimes it's even a little painful. It is extremely effective.
Our stores don't hide it behind counters either, thankfully. But I'm sure if you wanted to buy 10 boxes of it, they'd be quite suspicious.
Our way of limiting the illicit use of the drug? Put fewer on the shelf, and restock regularly. Not enough to even bother stealing since you'd have to do it over and over again just to get high, and there's always some there when you actually need it for sinus symptoms.
They definitely are. I was born with major sinus issues, and my doctor had me on an abnormally high dose of pseudoephedrine all throughout my teenage years to treat some of the symptoms.
As a kid, my mom would take me to the pharmacy to fill my prescriptions, and I guess the sight of a mother with her stuffy red-nosed child wasn't very suspicious to the pharmacist. But when I got older and would go to the pharmacy myself, I would often end up going home empty-handed with my prescription unfilled, because the pharmacist would see a scruffy teenager trying to buy a few boxes of something that can be used to make meth, and just refuse to give me any of it despite having a prescription on file for years.
Even when I was allowed to buy it, I could never buy more than a month's worth at a time, and it had to be when I was about to run out, otherwise they'd tell me I needed to come back in a few days. Led to a lot of "sorry, I can't go on that camping trip because I need to renew my prescription during those specific days or I won't be able to breathe for half the trip"
I wish the alternatives worked, because I would have much rather used them.