The Iron Throne was melted on accident. No, really.
TV and Movies
Game of Thrones' eighth and final season climaxed in May. The response to it has been mixed: Over a million fans signed a petition for it to be remade, but it also scored 32 Emmy nods. One of those Emmy nominations is specifically for the season finale, The Iron Throne, which was nominated for Outstanding Writing For a Drama Series. As part of that process, the script for the episode has been made available to the public.
There are a bunch of takeaways for the script, but the biggest one is about Drogon. You'll recall that Drogon, Daenerys Targaryen's remaining dragon, was enraged by Daenerys' death, and in a fit of rage he dracarys'd the hell out of the Iron Throne, melting it away to nothing. Why did he do that? Well, dragons are smart, so he was probably protesting against the symbol of the power-lust that led to Daenerys death, right?
Wrong. The official reason, according to the episode's script, is just, well, because? Drogon's paroxysm of fire wasn't really aimed at anything, and the Iron Throne just happened to be where Drogon unleashed his flames. Really.
An excerpt from The Iron Thrones' script.HBO
As you can see in the above excerpt, the script refers to the Iron Throne as "not the target of Drogon's wrath, just a dumb bystander caught up in the conflagration."
The criticism heaped against HBO for the final season mainly had to do with lack of both plot and character development. Plot twists like Daenerys' becoming the Mad Queen could have been good, the argument runs, but it wasn't built up to in any meaningful way, making it feel like ad-hoc fanfiction. The reveal that Drogon melted the Iron Throne for essentially no reason will do little to sway this criticism.