City passes are mostly a lousy deal unless you're zipping here and there all day every day. Pay per use is almost always a better deal but you need to know the particulars and get the right card/amount.
That’s the whole point. Tourists won’t really care if they spend more than they have to, and they don’t have to worry about it at all. Regulars and the price conscious will go the cheaper route.
Tourists will often just take taxis. Why fool around with figuring out the particulars of the local mass transit for a few trips over a short time.
Last time I was in Copenhagen I asked at the hotel desk how to get to the airport on public transit and the guy said just take a taxi it will be faster and much easier for you.
It depends on the city and where you're staying. Heathrow to much of central London can literally be about $100 cheaper on the tube and just as fast if you just have carryon luggage during normal times of the day. (Don't remember the situation last time I was in Copenhagen.)
I agree that tourists in an unfamiliar city will often just take a taxi by default though.
True, but I often find them worth it to not have to worry about buying appropriate tickets for every journey when I'm a tourist in an unfamiliar city. And on many transit systems, the options seem to be, "Be a local and get an affordable pass or reloadable card, buy individual tickets for every journey, or be a visitor and buy a moderately more expensive tourist day pass."
This is extra true if you're traveling with a family including kids, as I often am.