but the point of a lockdown should be to minimise your time outside
I guess this is a / the point of contention? My priority is minimising contact with other people, especially indoors.
The broader definition would be that the point of lockdown is to minimise transmission of the virus.
Both "minimising time outside" and "minimising contact with other people" both help achieve this in different ways, and it's impossible to say how effective each one of those is in relative terms, but there is no false dichotomy, people should be trying to do both.
I'm not making the "minimise time outside" thing up. It's clearly stated in the guidelines (with no weasel exception clauses):-
https://www.gov.uk/guidance/new-national-restrictions-from-5-november2. Staying safe outside the home (Social Distancing)
You should minimise time spent outside your home and when around other people ensure that you are two metres apart from anyone not in your household or support bubble.
Remember - ‘Hands. Face. Space’:
* hands – wash your hands regularly and for 20 seconds
* face – wear a face covering in indoor settings where social distancing may be difficult, and where you will come into contact with people you do not normally meet
* space – stay 2 metres apart from people you do not live with where possible, or 1 metre with extra precautions in place (such as wearing face coverings or increasing ventilation indoors)
(That's the whole of section 2 in case anyone thinks I'm doing any selective quoting.)
People are reading the "exercise" exceptions and (IMHO) pushing the boundaries of this whilst conveniently forgetting the other main principles of the guidance. That's all.
I will be getting back into running, and exercising outside, now that the swimming pool has shut and I can't play 5-a-side football (outdoors). But I'm choosing not to get back into cycling as I can get enough exercise in a few hours a week of running, getting a similar exercise load on the bike would have me outside for much longer and further afield. So I'm doing more outside exercise than before, but I'm choosing to keep this to the minimum I feel necessary.
Everyone will have their own opinion on where things cross the line to "excessive" and, for me, a 200km Audax is beyond that line given my thoughts on what the lockdown is trying to achieve.
But, again, it's funny that if you take away the possibility of the AUK validation of such a ride then for quite a few people (not everyone though) the necessity of doing such a long ride suddenly dries up. If this is the case you've got to ask yourself whether the original plan is strictly "necessary", and only the individual concerned can answer that question (and I'm not interested in any individual's answer).
I'm not trying to "ban" anything but I do hope that AUK decides to suspend validation, but that still doesn't prevent people from going out and doing a long ride. I wish they wouldn't in the light of things. I'd just like to see the carrot enticing people to do things that aren't strictly necessary being taken away for the period of the lockdown. Grumble at me all you will for this opinion, I'm really couldn't care less.