Probably because it is doing the rounds on social media as being of London and most people wouldn't even bother to question it unless they were familiar with one or the other or both. The only thing which clued me in really was the wrong kind of bus for London.
Initially I took it to be High Holborn heading west, at the j/o Kingsway/Southampton Row, but the buses don’t look right either, plus there’s no right turn from Kingsway into High Holborn, they’d have to go to the next lights and turn right into Theobalds Road, then right into Drake Street, carry on into Procter Street, then left into High Holborn.