I go to watch Blaze at the Skydome, never seen a traffic warden. Last week Team GB played there, was a Sunday night and pissing down.
Game was 5:30pm and most roads near the Skydive are 30 mins max until 6pm. Saw 4 traffic wardens on my 5 minute walk to the venue.
The council must think the city itself and city centre in particular are doing so well it doesn't matter if they annoy people and put them off a return visit. Apparently did the same at the England Women game at the CBS.