Why do parking restrictions end at 7 pm?

The evening ride - what a contrast! Cars in the bus lane, parked cars in the cycle lane, more traffic and more jostling for position at junctions. And more congestion.

Too much danger, too much unpleasant car-dodging even for a seasoned veteran cyclist like myself. And why do the parking restrictions and bus lane operation periods end at 7PM? Some of us don't have 9-5 jobs, you know. And some of us like a cheeky half-pint after a hard day down the salt mines. It's getting dark in the evenings, you know, so after 7PM is exactly the time you need more segregation from motor traffic.