Wait what!?

My sentiments, exactly.

I'm with you.

Woah that's frustrating. If even the mangaka isn't satisfied with the end - as a reader (and a leeching, second hand-one at that), I wouldn't dare to judge a manga, rather I'd voice my own opinion, knowing that everyone's got their own tastes.
But seeing as the mangaka wrote "I couldn't wrap this up, so frustrating how powerless I am" - that's just sad.