I really do not think it’s confusing. It’s not rocket science, and has been well explained by lemongrove.
No Mollypussy it’s most certainly not unfair to couples. This is about combating loneliness for people who live alone, such as my mother. She has been totally isolated for twelve weeks. She is 92 but not shielding. She can now visit us in our home. She can now enjoy a meal with us indoors. This week we have been visiting her in the garden at her sheltered apartment but now she can visit us in our house. You should think yourself lucky Mollypussy that you were not alone, and had the company of your husband during lockdown. Many others like Maw and other Gransnetters have been, like my mother, in lockdown alone. This measure is for them.