And to answer
Why do so many not like Deathly Hallows or Half-Blood Prince?
The former [
Deathly Hallows] was actually a good set of films, Rowling clearly wrote the book with it being adapted in mind because it's just not well-paced as a book, waaay too much action at the end and too much padding in the middle in the forest, also the character dumps for Snape and Dumbledore were clumsily added. Too much going on at the wrong parts. But David Yates' direction streamlined out those excesses and actually made the forest scenes feel like something meaningful [if with a bit of a Harry/Hermione shipping despite Radcliffe and Watson lacking that kind of chemistry]. Would've been an A if Snape's memories were better elaborated [y'know the whole reason he and Lily fell out...the movie makes it look like Lily just suddenly went with James for no reason except "he's hot"] and Pettigrew actually got killed off rather than forgotten.
As for
Half-Blood Prince, the book was a rom-com with only an air of mystery, the only things of note in the whole book were Dumbledore's death and the origins of Voldemort...and the movie decided to drop the whole element of mystery which was important to explaining Snape while playing up the rom-com stuff. I can't bring myself to hate this one as much as
The Goblet of Fire because, one stupid added scene with no payoff aside, at least it felt like the material it tried to be, and Michael Gambon did good as Dumbledore.