A 68-year-old Sydney man was beaten to death this morning while driving his regular bus route from Maroubra to Circular Quay, after passengers were offended by his positive attitude.

One passenger described the incident as the result of “justified rage” in the face of “rude happiness”.

“This was the manifestation of built up anger reaching breaking point because of the crippling sads that kick in as work looms just after Sunday brunch,” he said. “Monday morning is no time for a cheerful smile.”

Another passenger was also sympathetic to the accused attackers. “The bus ride in is the last safe place we can freely express our depression about heading into the office – it’s almost bonding seeing so many others on the verge of breakdown,” he said. “The last thing we need is a friendly bus driver smiling and saying what a great day it is.”

Transport officials agreed. “We understand certain bus drivers forget that while they simply drive a bus, the passengers on board actually have to get off and go to work,” a spokesperson said.

The driver was set to retire next week.