I liked SKT and there's a lot of good sections, but it has problems.
There's few plot hooks for the adventure and the story doesn't really go anywhere. There actually isn't really a story per se, just a big sandbox to wander through. It's not so much an adventure but a series of set pieces and dungeons that player characters stumble between.
The actual story of the "event" isn't even really resolved or addressed. The adventure just ends and things are assumed to go back to normal somehow behind the scenes. Which is a big friction point for the last third of the adventure, because the module assumes you're going to focus on finding the titular Storm King when really every player will be much more interested in restoring the Ordning, which will stop all the giant misbehaving that's actually a problem. Finding Hekaton doesn't stop the frost giants or save any of the "small folk".
I blame Chris Perkins.
Okay, that's a dick thing to say, but hear me out.
I had some issues with Curse of Strahd and the lack of direction between locales and hooks. But then I watched him run the adventure for Dice, Camera, Action and saw how he took what was in the pages of the book and expanded on them, drawing on the book to tell the story of the Waffle Crew. Some masterful DMing. And seeing that in action, I can totally see him doing something similar for Storm King's Thunder: pulling on the motivations of the giantess princesses and having them scheme in response to the players, or having them show up earlier with machiavellian intentions. Reading between the lines of the adventure and fleshing it out to tell his player's stories, with the actions of the party and events of each session affecting the narrative, and the adventure being a big bag of tricks and scenes that can be drawn from as needed by the story.
That's great for a master DM. For Chris Perkins. Someone who has read the adventure a few times cover to cover and knows which NPCs they can bring in on the fly, and feels comfortable tweaking the adventure. But it's less useful for people who need those rails and set plots, who don't know the adventure front-and-back, who don't feel comfortable adding moments or extrapolating actions of NPCs. It's ill suited to rookie DMs, organized play DMs tailoring things less to the party, people running a published adventure because it's lower prep, etc.
The above also makes it less fun to read. Adventures with a stronger storyline are more fun to just sit down and skim. And the potential reactive story elements are less apparent upon reading, making it less exciting and thus less desirable to play.