Do we think random people in Gotham find Batarangs wedged into walls or lying around and decide to take a shot at throwing them, and it slowly becomes a Gotham city staple you can play at the arcade/bar? (Everyone is surprised at how hard it is to throw them with accuracy and the force needed to have any sort of impact)
The Batkids delight in either pretending they don't know how to (as civilians)/alternatively flirting by demonstrating their expert ability to nail phone numbers to alleyways.
There are also definitely collectors who trade these Batarangs and organize them by era based on material, and you get extra acclaim if you know the provenance of the Batarang (fished out of the harbour or taken out of a GCPD squad car).

















