[Nyororin]

Let me tell you what`s worse...

When a publisher in Japan suddenly decides they no longer want to continue a series, and you get this really really crappy "Try to tie the whole story up as fast as you can" final chapter.

When they just stop publishing in English, at least you could still read the Japanese original. But when they force the series to an end, that`s it.

My favorite example of this is 花田少年史. An excellent series which didn`t have all that much popularity in the original run... So they canceled it, and the author made a speedy (read crappy) ending for it.
Later on, it gained a lot of popularity thanks to the author`s next work, and sold a TON of compilations. It ended up being made into an anime, and then a movie.

It was the type of series that could have gone on for a very long time... but they killed it at the source.