Part of the trouble is that the kind of on-road cycle lanes we're talking about in the UK aren't normal lanes in various respects, including sometimes legal ones. Even to the extent that they are, they are often created by literally nothing but painting a line down existing roads to mark off an area much smaller than the relevant policies call for. No extra space is created, nor any real physical separation or protection added.
This results in exactly the kind of them-and-us culture I was talking about, where a lot of drivers who don't cycle themselves see a cycle lane and think bikes should stay in it at all times, while anyone who has ever cycled significantly could tell you that this is completely unrealistic because the lanes aren't wide enough for anyone to do so and still make sensible progress even before you consider all the extra hazards that tend to happen towards the side of a road where the cycle lane is.
Consequently a lot of faster and more competent cycles will disregard the lanes and cycle in the main traffic flow when conditions dictate, and a lot of ignorant and selfish drivers will then illegally harass and intimidate the cyclists for riding in the main traffic lane and slowing them down marginally. Many drivers also pass cyclists who are in a cycle lane far too close, and one of the well established benefits of removing road markings for explicit lanes is that drivers do then move out significantly more and pass cyclists at a safer distance.
For me, the only truly credible solutions to today's them-and-us culture involve providing a decent standard of facilities for both groups where conflict is designed out in the first place. Much better designs than what we currently use in the UK are known -- the Dutch typically do these things well, for example -- but they cost significant amounts of money, particularly to implement them retroactively on existing road layouts, and so far the political will in the UK just doesn't seem to be there to spend it. In some places, particularly older cities with historical areas and narrow streets, there simply isn't a good solution as long as so many different types of vehicle are trying to share the same road space.