why do people think the passenger pigeon is still around?

I don't think any scientist thinks they are still around.

There are lots of species that are "pigeons" or "doves" in the United States. Perhaps people think of the common Rock Pigeon in our cities, or have heard of Carrier Pigeons, or have seen Mourning Doves or other Dove Species and confuse that with the Passenger Pigeon. But if you asked 100 birders about it or 100 biologists, I think no one would tell you that species is still alive.

There is, of course, discussion on two other presumed extinct birds: the Eskimo Curlew and the Ivory-billed Woodpecker where it may still be an open question.

People are always mixing up the Passenger Pigeon with the Carrier Pigeon and the Homing Pigeon - I can't tell you the number of times I've corrected that over the past five decades.

yes it did go extinct on September 1st 1914 but people do get mixed up with the passenger pigeon and carrier pigeon and homing pigeons wow

People are ignorant. Look hard enough and you will find people who think that you can find dinosaurs if you hunt through the jungle or a pleisiosaur in Loch Ness.

The only passenger pigeons "around" are stuffed and in museums. I had the pleasure of holding a stuffed specimen that had been overlooked in a university collection once. I would much prefer to have seen a live one.