Bad endings everywhere

Somebody once told me: "you can't judge something by its ending" to which I replied "Sure you can. A bad ending in an anime, movie or series is like having a stripe of line painted across a work or renaissance art. It doesn't matter how good the overall is, you'll always focus on the stripe, or in the bad ending. Nobody starts watching something expecting for a lame ending"


There are many reasons that can cause an anime to have a terrible conclusion. The most common are:


1 - The original work's (manga or novel) ending is lame and the show just reproduces the original ending. (Specially forced happy endings)
i.e.: Angel Beats!, Clannad After Story


2 - The series isn't an adaptation of a manga or novel (a.k.a. "original animes") and the script just happened to be bad overall or in the ending.
i.e.: Yumeria, Seikimatsu Occult Gakuin


3 - Animes that start before the original work is concluded, approaches the original work's story and is halted with an open ending.
i.e.: (There are dozens of examples here) Gantz, Tenjou Tenge, etc


4 - Story completely different from the original or improvised endings resulting in something with a very low quality
i.e.: Fullmetal Alchemist, Rurouni Kenshin


5 - Anime doesn't get the expected response (low ratings) and is decided to be cancelled.
i.e.: D. Gray Man, Mobile Suit Gundam (the original one)


Lately, it's been more and more common to come across bad endings in animes which made me stop to think.What the hell is wrong with those studios? Except for when the original work already has a bad ending, all the other cases are to be blamed on the studios. Don't they realize that this ends up being negative for them?I truly fear an overall drop in animes qualities. Actually, this can already be noticed if you stop to think on the last, let's say, 30 animes you watched. How many of them had a satisfactory ending?


I understand that the concept of bad ending can vary when we talk about case #1. But when it comes to the others we usually have a consensus and those are usually the vast majority of the shows out there. I think that this could harm the animes production in a way that many people will stop watching shows from a certain studio or that they know to be based in an unfinished series. As a huge japanese animations fan I'd hate to see a drop in production or in quality shows due to such a silly reason.


My Top5 Worst Endings:


1 - Clannad After Story (forced happy ending just for the sake of it)


2 - Densetsu no Yuusha no Densetsu (totally open and incomprehensible ending)


3 - Mai HiME (forced happy ending just for the sake of it)


4 - Arakawa Under The Bridge x Bridge (builds up for 2 seasons and ends up with nothing happening at all)


5 - Seikimatsu Occult Gakuin (the ending seemed so rushed, as they had forgotten that they had to finish this series and only remembered it on the last episode)


Honorable mentions: Code Geass R2 and Soul Eater.