I didn't mind that they decided to destroy Vulcan I just didn't care for the way it was treated so cavalierly. It was nothing more than a grand spectacle without any further attention given to it. That is what I thought was its failing.It was about mixing things up again in the story, and not pushing the same old reset button shit that happens all the time in Trek.
Remember when Spock sacrificed himself to save his friends, Kirk blew up the Enteprise, and the Klingons murdered Kirk's son? They were huge and unforgettable moments. Movies are made for big things to happen. Yeah... I know the first two things were undone but you have to admit seeing those events were shocking.
In TWOK, Spock died saving the Enterprise. In TSFS, Dr. Marcus was fighting for Spock and Saavik. The "death" of the entire planet of Vulcan served no purpose. It was not heoric. It was no sacrifice. It was more or less random in the timeline in which it existed. Sure, that kind of thing happens in real life. But, this isnt' real life, and in fiction, the death of a major character is usually for something. And, in a sense, Vulcan was a character.
What if Spock had died in a meaningless way in TWOK? Just killed at his station in an attack by Khan. Would that be satisfying? Would we defend his death as necessary anyway for the future growth of Kirk's character? That's the only excuse being used for having an entire planet of six billion people destroyed. Just having Amanda die would've been poignant enough and served the purpose for Spock's future character. What was done instead was literally the definition of overkill if the only purpose was to affect the character of Spock. And, what other purpose did it really serve? Why couldn't Earth and Vulcan have been saved? Or, maybe saving Vulcan would've left no time to stop Nero from destroying Earth. How that would've been handled would've added real depth to the story.