The concept of the wall of trivia I think belongs to Mary Goulding. She is the first person I saw present this idea.
The wall of trivia allows for two people to keep an emotional distance from each other. Closeness, attachment, dependence, vulnerability is wanted to be avoided by at least one person. This is done in a non conflictual manner by couples who are not comfortable fighting and arguing.
The wall of trivia in essence uses the distraction technique. The couple avoid closeness or contact by distracting. They talk about things other than the relationship such as the children, the mortgage, work, sport, religion, home renovations, the garden and so forth.
Why would people want a wall of trivia in their relationship
Fear of closeness
Wants distance in relationship because there is a strong unresolved symbiosis, smothering by one party of the other, lack of clear defined boundaries in the relationship
Discuss things (trivia) to avoid marital problems because the possible consequences of this (Divorce) are just too daunting
The scars are too deep from past exchanges where either party said or did very hurtful things. The Free Child simply refuses to allow itself to get close again and be hurt like that again.
A physical and/or psychological affair happening. At least one party is getting their emotional needs met else where.
There is a life script to end up alone
The wall of trivia is usually used by non conflictual couples. People can use anger to do the same to create an emotional distance in a relationship. But some couples do not fight much so they can use the wall of trivia to achieve this.