A LOT of animes end that way. A LOT of them. Even when the manga's still going, once the ratings slip, it's over. They have to scramble to anything as close to an ending as possible. Soul Eater had a rushed finale that didn't even reflect the actual Manga, which was still running the story arc before they had to chop it off there. But nothing beats what happened with Shaman King. Not only did it never get the TV finale it should have, but it took years for the original Japanese publishing company to come to their senses and give the manga an ending. That's right. Even the manga was finished too soon, because reader opinion polls dropped, leaving the comic itself unresolved... until later, of course when they were playing nicey nice with the artist.Inuyasha: NOTHING was resolved it just ended! Granted the manga kept going and had an actual and decent conclusion but the anime just quit.
But then again, there's always what happened with Saint Seyia. They ended the show after many episodes, leaving the last arc unresolved. it took them decades to make a series of DTV episodes closing the series off. No wonder why Lost Canvas wound up going to TMS.
That said, Inuyasha, I don;t hate, but I find it overrated... especially since I think Rumiko Takahasi's best works are Ranma 1/2 and Lum the Invader. You haven't LIVED until you see Lum the Invader.