What a ridiculous article. I've used London Cycle Superhighway 3 on many occasions, which is largely bi-directional, and it is a joy to use compared to any on-street infrastructure in Edinburgh.
Drivers pulling out of side streets respect the stop lines, which require them to stop before crossing the cycle track. Drivers look before turning into side streets - well, as much as they always do.
I think bi-directional lanes are used for two main reasons. They take up less room than two separate segregated lanes and are cheaper to build. It would be great if we lived in a world where road space and public finances were no barrier to progress - but we don't.
Also - who knew that city cycle campaigning began in 2007 with our hero "...a lone voice in the wilderness regarding bicycles as transport in cities, with only testosterone-driven, frothing at the mouth sports and recreational cycling blogs for company in the woods".