"simple disapproval of law-breaking"
There are people who cycle who disapprove of people who cycle who break laws.
There are people who cycle who disapprove of people who cycle who break laws that relate to cycling.
There are people who cycle who disapprove of people who cycle who break laws that relate to cycling because of 'what other people might think'.
There are people who DON'T cycle who disapprove of people who cycle who break laws that relate to cycling.
There are people who disapprove of people who cycle who break laws.
There are people who disapprove of people who break laws.
Etc.
Simple (to me) is that people who ride bikes (who also happen to be most people on this forum) shouldn't inconvenience/endanger other people especially people on bikes AND (perhaps particularly) pedestrians.
It's easy for the police to say 'you can't do that it it's illegal'.
It's easy for people to say there was no-one crossing on the Green Man/walking on the pavement I'l take the 'illegal risk'.
The problem is there are people (on bikes) who don't know 'the law'/don't care.
These people can/do endanger others - or at least 'put people in fear' - same as on the canal. Even ignoring the legality/desirability/enforceability of the "6MPH" cycling speed there are undoubtedly people who have no care for others 'in the way'. THEIR 'right' to get to work/home as fast as possible overrules everything.
Back to roads/pavements.
It's fine to not want to be lumped together with other people 'who happen to also ride bikes'. It's also reasonable to think that just because some people who ride bikes do things that are 'disapproved of' (legal or otherwise) - 'we' (individually and collectively) SHOULDN'T feel guilty/responsible.
The problem is that we don't live in an entirely reasonable/rational world!
Like it or not, some people see 'bad' cyclists and imagine that bad = all.
Fine - 'their problem' etc.
Less fine if some of those people have 'seen' cyclist at too close quarters doing something inconsiderate (legal or otherwise).
Of course some pedestrians are just as unpredictable/rational as some people on bikes!
I suppose it's a question of whether 'it doesn't matter' or 'it's too late, more people cycling means more disregard for 'laws' - like London.