So why do cyclists get a bad name?

As above... seen plenty of terrible cycling out there, seen plenty of terrible driving too... I am fairly comfortable in saying that none of it really matters.

Yes, I can see why a car driver might get annoyed at cyclists perceived lack of self preservation, but honestly, the benefits of driving a car come with responsibilities ... you the car driver, drive the lethal weapon, its your job to keep people safe from that, not cyclists/pedestrians job to keep out of your way...

If cyclists are bumbling about in a world of ignorance and incompetence that's their right, they would need to do something monumentally stupid to cause anyone any serious damage... therefore its actually fine if they don't always use the greatest care or make the most sensible choices out there.

This stance is equally relevant when comparing the serious cyclist enthusiast and casual rider... the faster you cycle, the more responsibility you bare, as you are the one that will ultimately cause the damage or get hurt. Take responsibility for your actions, your speed and conduct around these less competent riders... hell everyone, and honestly, really quickly it'll all seem a lot less annoying.

100% of riders in my household think all drivers are arseholes
100% of drivers in my household think all cyclist can be a pain in the arse.
100% of cyclists in my household drive
100% of drivers in my household cycle
100% of the above needs to be taken with a pinch of salt.

Conculsion,
You enter life with nothing, leave with nothing, what have you lost? Nothing!

Interesting stats, but a complete red herring.

every single day I am overtaken by a long line of vehicles when I am travelling at 70 on the motorway - giving motorists a bad name

every single day vehicles run red lights on the slip road of the light controlled junction I go through - giving motorists a bad name

every single day when walking around town there are vehicles parked either partly or completely, all 4 wheels, on the footpath - giving motorists a bad name

every single day I see drivers on phones, even doing their make up - giving motorists a bad name

do I need to continue....?

Go ahead and try to reinforce the "bad bad cyclists" trope. Count how many times you see a cyclist kill someone by running into them while doing something stupid.

Then count how many people die as cars smash into them during the same period.

Then wonder why drivers don't have a "bad name"

Then you will realise why everything in the original post is very close to irrelevant.

A few random UK accident stats:

For the UK, from 2008 to 2012 (inclusive), out of the total numbers of pedestrians killed in single vehicle collisions with vehicles in any location, cycles were involved in about 0.4% of fatalities and around 1.4% of serious injuries, while cars were involved in about 68% of pedestrian fatalities, and 81% of pedestrian serious injuries:
http://www.ctc.org.uk/sites/default/files/file_public/pedestriansbrf.pdf

In Scotland in 2011, there were 168 accidents caused by disobeying an automatic traffic signal. In 9 of these accidents the vehicle responsible was a pedal cycle. So around 95% of all accidents in Scotland caused by ignoring traffic lights are caused by motorists
http://www.transportscotland.gov.uk/analysis/statistics/TablesPublicatio...

Edinburgh's road safety figures for 2004-2010 show that motorists were responsible for 72% of accidents resulting in serious injury to cyclists:
http://streetsaheadedinburgh.org.uk/info/4/pedestrians/79/road_safety_st...

There are around 5 deaths every day in the UK caused by motorists.

I think the accident stats suggest some road users do have a bad name. I don't think it's cyclists, despite the behaviour of the "bad apples" that you identified on your journey.
Perhaps we should start challenging the "cyclists give themselves a bad name" statement, instead of repeating it, and point out the road users who are really earning themselves a bad name by actually causing accidents, injuries and deaths?

It's not just London. They are everywhere. I was out and about cycling last week and there were four "fair weather" let's go for a fun ride down a quiet country road, all riding abreast in a straight line across the road. Three adult men and one kid. I'm riding at about 22-25 mph as I see them on the horizon, slow down slightly and decide that there's enough room for me to pass them (obviously keeping an eye out for any oncoming traffic). Just as I get closer, the kid riding with them decides to swing out from their leisurely formation to the other side of the road to ride on the opening of a farm track on the field. I have to slam on the brakes, swerve out of the way, managing to unclip myself in time to stop myself ending up in a roadside ditch. The three adults didn't say a word to the kid. Imagine if that had been a car behind them.

I have also nearly run into a woman doing that chat thing on a mobile, one handed thing - she actually stopped her bike suddenly saying something like "I know! Ha ha" on her mobile. No warning, wasn't aware of her surroundings at all. And there's me having to cycle slowly behind her, watching and second guessing what she will do next. And there's another one who bikes round my way. Watched her the other day wobbling around on her bike; car comes up behind her. The driver slows down, keeping his distance and then indicates and passes her slowly as someone would do with a horse rider, she waves to thank him for giving her room, at which point she decides to steer her bike right towards the side of the car and shouts at the driver as if it's his fault.

With idiots riding around like that, I'm not surprised so many motorists get peeved (even if some do it just because it seems to be the in thing at the mo to have a go at cyclists). But then we all get branded the same.