Is it time to start calling out bad cyclists?

Because the cycle lane that he was aiming for on the other side of the lights is on the left hand side of the road. If you are going straight on and prepared to take the lane, then I agree that you should put yourself in the middle of either of the car lanes. But if you want you use the bike lane then your suggestion is that you filter up the left of the traffic, pull across in front of the cars and then, when the lights go green, immediately pull over to the left again to get into the cycle lane. Seems pointless to me.

Based on what the both of you are saying all cyclists coming to the lights should be in single file. Given the volume of cyclists that typically use this junction your joint stances are unrealistic. There is enough space - if you're considerate to the fact there's a big junction to the left- for two lanes of cyclists. On your search did you see any compulsory give way for motorists to cyclists?
The answer: no. If I had been a tired truck driver racing the clock with a green light with a faulty sat-nav unsure of my surroundings then I fear for folk that religiously stick to this position. NB I wasn't trying to teach him a lesson.

No. Both of those lanes have straight-on arrows in them, which suggests that you can go straight on from any point of the road. When coming to a junction I assume that cyclists on the left of the road may be going left or straight ahead (especially if there is a bike lane on the left hand side of the road ahead) and that cyclists in the centre of the road are going straight ahead (I'm assuming no right turn is possible). The only thing that I intuitively discount is that a cyclist who has put himself in the middle of the road will turn left, precisely because it will require him to cut across a stream of cyclists going straight on.

Unless you suggest I undertake along the straight of the bridge, at some point I have to try and get into position for my left turn early but unless you're fairly aggressive no one (on a bike) wants to give you way to get there.

Instead you create an entirely new problem by acting in a massively unpredictable and counter-intuitive way.

I'm not sure I can agree with that^
If you ask motorists what they hate dealing with nowadays it's left turns due to the heavy streams of cyclists on their left usually going straight ahead...a very recent and unpredictable phenomena hence that mad max/battle mode feel on commutes that I don't remember 5 years ago- a behaviour that I'm not about to help normalise with my actions- irrespective of what the paint says.

Though if staying out of the gutter makes me unpredictable then so be it.

What is your specific objection to being on the left if you're turning left. Assuming you can get ahead of the cars, you should avoid being left hooked. If you pull into the centre of the lane then you create the problem that cyclists going straight on will filter up the left of the cars into the ASL box, not knowing that you are there. **How are they then meant to position themselves? Should they manoeuvre round the back of you so that they're on your right? If you pull up on the front left, then those going straight on can easily move to your right and those turning left can queue behind you. This is how every other junction seems to work.

I don't have an objection to being on the left per se my concern is that on smaller tighter junctions sticking to the left is an invite to taxis in a rush/boy racers/motor cycle couriers and other inconsiderates to try and overtake on the bend. <- Do you think that is a good thing? If cyclists had the torque that motorbikes have then none of this is an issue but if you don't you should take a stronger position that obliterates that chances of SMIDSY being used against you. Once you're over/past/have turned the junction then drift to the left and allow faster moving vehicle to pass. But not ON the junction. As far as I knew, on most junctions only one vehicle should passing at a time NOT a royal rumble free for all.

I fear too many place too much faith in cycle lanes and paint in general: Most aren't aware that a hatched line = anyone can go into it.
I'm yet to see fines issued for the drivers that routinely park on the Waterloo Bridge cycle lane (northbound) that is a SOLID line.

Look at London Bridge (southbound) junction with Tooley Street: There are arrows suggesting the left lane is for.....you guessed it! left turners. Yet those going straight ahead stick to this lane so I'm stuck with keeping motorised vehicles at bay, then I'm swarmed by those going ahead in the wrong lane. THAT is unpredictable.
IMO what should be happening is those wishing to go straight need to get to the middle lane before the junction, if not, at the least be in the very right of the left lane. How? A look over the right shoulder. If there is anyone there that will benefit from the signal then do so. That would be predictable to other road users.

Nope, I've had a good look on streetview and know if from the various wranglings over the redesign. One thing we can agree on is that the road and bike lane layout is shite!

Indeed but there are numerous junctions like that mentioned above where cyclists insist on sticking left when it's just not logical or safe at all.

Sorry for being so wordy.