Normies talking about Game of Thrones would be a good thing, were Game of Thrones actually good.
Things have changed now due to the internet, but in the past, everyone watched the same TV, because television options were limited. When someone talked about The Six Million Dollar Man or some shit, everyone knew what they were talking about and it became an easy way for people to bond. It was a homogenizing cultural aspect, and healthy, as it enabled a society to have something in common.
The real issues are:
1) Game of Thrones is absolutely pathetic, the last episode was was unwatchable because the story now revolves entirely around extremely unlikable women while the most important character, Jon Snow, just stands around mumbling and being yelled at by literal children. It is more agenda than story.
2) People have literally nothing else going on in their lives besides Game of Thrones, they have no self-esteem, no values, no higher ideals, so Game of Thrones is the ONLY thing tying them to the larger society, rather than one aspect of many.
Most of the normies who watch Game of Thrones really understand nothing that is happening in the show, they can't discuss it, they just absorb it, passively, on the most superficial level, and talk about it just because they have nothing else to talk about with other people. That is the real problem.