The problem is that parking contractors are not actually interested in preventing obstructions - they're interested in issuing tickets. If someone is unloading or dropping someone off, they would rather issue a penalty than ask the driver to move on (in fact, the latter could lead to the warden losing their job). Wardens have quotas to meet, which leads to predatory tactics (e.g. counting down the seconds until the restriction window starts) to catch people out. The objective is revenue, not public service. Cue the usual high-and-mighty, anti-motorist "just don't break the rules" posts. But meanwhile, in real life, shit happens. Wardens should be using judgement as to whether a ticket really is warranted.