Honestly, I feel that people are purposefully being blinkered to the whole idea of why these rules exist, and finding issues where there aren't any.
If the government said that you can meet people in your garden, then people will push the boundaries: some gardens you need to walk through the house to get to; you would be offered tea, share condiments, cutlery, a pack of biscuits etc; you'd use the toilet. It starts raining and you end up inside on the sofas (I think the unusual good weather for a long period has made us forget that it often rains in May!)
In a public park you have peer pressure, so are much less likely to hug, kiss, keep less than 2m.
The government expect people to push the boundaries, so when they say meet one person, they expect people to actually meet mum and dad, or sister and brother-in-law. If they said you can meet 2 people, people would push it to meet wider family: parents plus brother and nephew. If they said 4 people can meet in a park, people would push it to 6 or 8 people.
For the ridiculous people saying 'I can arrange a viewing if selling my house so I'll arrange for my parents to view my house'. Are you going to hug the house viewers? Will they use your toilet, taps, fridge? Will they stay for a few hours? Will they want to interact with our children? Will they use your cups for a drink?
For what it's worth, I have never voted Conservative, I think there are so many ways that this government have handled this terribly, and I don't trust politicians to do anything in my best interest. But what I do agree with is that they can't tell us it's ok to meet more family members in our garden because people will take that as a free pass to have a party.
YOU might meet in a garden that is accessible from the road, not touch anything and not use the toilet (If so, crack on- you are using common sense). But if MN has taught you nothing else - there are a HUGE number of idiots out there. Read the CF threads, the 'Who's worked in retail?' threads, the threads from anyone who has worked with 'the pubic'. Using the toilet at your parents, accepting a cup of tea from a neighbour, hugging your family, may all be tiny things with minimal risk- but if the government say ok to this, then it all adds up to transmission.
Half the public are saying 'lock us down further' and half are saying 'let us out to hug our famlies'. The advuse wehave is actually a middle ground.