Well, it seems kind of absurd, but why doesn't a thermometer have a world model? Taken as a system, it's "conscious" of the temperature.

If you scale up enough mechanical feedback loops or if/then statements, why don't you get something you can call "conscious"?

The distinction you're making between online and offline seems to be orthogonal. Would an alien species much more complex than us laugh and say "Of course humans are entirely reactive, not capable of true thought. All their short lives are spent reacting to input, some of it just takes longer to process than other input"? Conversely, if a pile of if/then statements is complex enough that it appears to be decoupled from immediate sensory input like a Busy beaver, is that good enough?

Put another way, try to have a truly novel thought, unrelated to the total input you've received in your life. Are you just reactive?