I think this was written by someone who isn't comfortable with extended periods of silence with their partner.
My wife and I barely speak or communicate nonverbally for hours sometimes, then talk at great length other times. We always give each other an opportunity to talk about our day or whatever else is important, but we don't talk about trivial things simply for the sake of talking. We're comfortable with silence.
Idk I took it more to mean "wow I don't want to start a deep, thoughtful conversation the moment I get home from work let me relax for a minute" while at the same time still wanting to talk to your partner. But I guess it's up to reader interpretation and I do seem to be in the minority here.
I just feel like a lot of people here are defining "small talk" as "a conversation that I don't want to have" rather than any meaningful definition.
I would consider stepping outside in the morning with your partner and stating "oh wow it's such a nice day today" to be small talk. It's a conversation without an end goal, sure, but I don't think it's as worthless as people are making it out to be.
I would say it is likely complex. One might also assume for similar simplistic reasons that small talk is primarily used by people who get insecure if someone else isn't constantly acknowledging their presence by talking with them about something.
Likely neither of those simplistic explanations do the full complexity of social dynamics justice.