I could go into detail on how I dislike his heavy reliance on highly detailed backgrounds and music to archive what should be done with good pacing and writing. If you need to explain the ending montage in the movie for people to fully understand what you really want to convey in the movie, then you're doing something horribly wrong.
I find a movie about an indecisive faggot who can't move on even with all the opportunities neatly laid out before him not as touching as most people make it out to be. Sure that really ain't the point of the movie, but it sure stands out more than what he intend to convey.
Oh, yeah, you can call it realistic, and many seem to praise it to be as such, but that doesn't make it good, nor entertaining. A work of art then? Sure, if you're just counting the audio and visuals.
But ofcourse, that's my personal opinion of him. I've liked his stuff since voices of a distant stars, in fact, I did a fansub of it and she and her cat. He's getting why over his head in trying to do complex stories, something he really no talent in. I feel that he should just stick to what he does best, creating CP.
Meh, only good thing about Makoto Shinkai stuff is the CP