I'm one of these people. I can smell an apartment roach infestation from the front door, every time.

And yes, restaurants always get the "sniff check" before we sit down. No-go odors are:

• bleach
• pine-sol (amonia)
• heavy perfume (think "Glade plugin-in")
• insects (roaches, etc)
• pet odor (wet dog, litterbox)
• sewage (usually a dry floor drain but that's still not okay)
• dingy carpet (think: "old movie theater")

The first two are obvious attempts at covering up something worse with "clean" smells, and/or the staff has no idea what "clean" actually means. And they obviously don't care what olfaction means to someone trying to enjoy a meal, which says heaps about what they think food service actually is. Everything else just speaks to the "I don't care what you smell" part, or there's something very wrong with how the kitchen is run. /rant

An example of a top-shelf dining odor experience? I once went to a Japanese restaurant at opening time. The only smell in the dining room was that of the specific kind of imported cedar in the cutting boards. This is traditionally cleaned with boiling hot water, and nothing else. This released a gentle woody and pine-y scent that just filled the space and invited the senses. I came hungry, but I sat down ravenous. The meal to follow was something I will never forget.

Edit: some clarification since this got some traction. I know that bleach and ammonia are s-tier disinfectants and absolutely necessary for food prep, health standards, and the rest. I use this stuff at home. My issue is with establishments that utterly fail at ventilating these odor and spoil the dining experience with strong chemical odors. Looking deeper I find very strong cleaning odors (long after opening hours) suspicious since it's very easy to splash stuff around, giving the impression of cleanliness, but not actually clean anything. Strong chemical smells also make it impossible to detect sewage, rot, mold, soil, and other things that would easily flag a restaurant. I'd rather not take the chance.

I can smell ants and cockroaches. I can also smell when someone has been in my house hours after they leave. Its annoying as hell to have this sense of smell since its considered rude to point out that someone stinks. To me its like they are screaming in a small room.

I assume people just can’t identify the smell of cockroaches until they learned it? Similar to people being oblivious to the smell of marijuana when not familiar with it.

I’m not sure I would recognize the smell of roaches if I didn’t keep them as food for other animals. Stinky little buggers.