Why is everyone down on The Dark Tower?

I've been pondering this for over a month now.
Why is everyone down on The Dark Tower movie?
Everyone should be down with The Dark Tower.
Did it deserve multiple 3-hour installments?
Yes.
Did it get them?
No.
Was 90 minutes too short?
Yes.
Am I tired of Universe-In-Peril stories?
Very.
Does this necessarily make it bad?
No.
My wife won a couple tickets to the movies. We spent them on The Dark Tower, even (especially) after hearing how bad it was from every critic and fanboy and Johnny-come-lately. I went because I love the Dark Tower Mythology. I expected a bad movie. Maybe if I didn't have the background knowledge from the gazillion pages of the books, I would have felt a bit lost. Don't think so but not sure on that one.
Did I get a bad movie?
No.
Did I get a great movie?
Hmmmm . . . .
Of course I suffered little disappointments that all gazillion and one pages weren't condensed and represented on the screen. But, really, that's about it. And compared to how much I disliked darlings like Inglorious Basterds and The Avengers, not to mention Batman Begins and bloated tripe like The Dark Knight Rises, The Dark Tower was not only not bad it was actually great. Not a great adaptation, but great entertainment.
I just sat back, stuffed my face with popcorn and thoroughly enjoyed seeing a few bits and pieces of my favorite series of books splashed across the screen. Good CGI. Great in-jokes for King fans. Idris Elba made a fine Roland. Matthew McConaughey looked a bit too mannequin-ish for my tastes but was calm and threatening in a way that I enjoyed. Top notch casting and performances all around. Seems a shame we're not likely to get this group together again.
The fuckin' low men? Nice little touch there.
The gunplay was top notch, even in a world inundated with topnotch gunplay (I'm looking at you again, John Wick).
but at an hour and a half, there just isn't enough of it.
of anything.
Still . . . .
I had fun. I saw a couple of my old friends for the first time in years.

Maybe I'll revisit their novels soon and hope that Netflix or HBO or Hulu gets ahold of The Dark Tower and does right by it with several well-produced seasons of Television.
I hope the movie (which doubled its tiny budget) inspires a new audience to read its source material and spawns the adaptations it deserves.
Do I want more?
Yes.
Am I happy with what I got?
Yes. Yes I am.