Peter Frimberley wrote:

Yes, they do this deliberately *because* of the idiot car drivers that
try to perform unsafe or selfish manoeuvres at traffic lights.

There is nothing idiotic, unsafe or selfish about using 2 lanes at
traffic lights where 2 have been provided. And it is perfectly
legitimate for the vehicle that arrived later to move away first.

Cyclists have been forced to adopt a similar stance, gone are the days
when the cyclist could adopt a path approx 1 foot from the pavement
and know that cars would give him a decent berth; so they have to
force the issue and ride in the middle of the lane at any tight spots,
to prevent any morons trying to cut through where it is too narrow.

Totally different situation. If a cyclist did not allow motor vehicles
to overtake by adopting such a position where it was safe to overtake,
the cyclist would be guilty of cycling without due care and attention
and consideration for other road users.

In a similar vein, any bus that straggles two lanes or refuses to use
bus laybys to prevent vehicles from overtaking is, in my opinion,
guilty of driving with undue care and attention and consideration for
other road users.