And the fun part is, just like Alan Moore in Watchmen actually tried to highlight the better parts of humanity, so were the (first four seasons) of Game of Thrones not the "dark, hopeless" world many name them as.
All Game of Thrones did was set out not to give its characters any slack for being the main characters. There was still a lot of uplifting and positive moments, especially when it came to highlight the love (especially friendship or familial love) people can have for one another.
The latter four seasons...well that was two bro-dudes that had run out of material to adapt (or were ignoring material they hadn't adapted yet) and just writing what they thought would be "kewl" or "subvert expectations, even if it meant ignoring the main plot.
Walking Dead...yeah...you got me there. But that series' idea was flawed from the beginning "A Zombie Apocalypse that Never Ends" creates a (fairly) static scenario that basically negates any hope for (long term) improvement. In that show it can only get worse.