Was the human reaper inspired by Neon Genesis Evangellion?

Depends on which canon you are following. Original one they allowed their mind/souls to be absorbed into the soulless Eva units. Because the connection was needed to allow them to be piloted and as a way to protect their children. In the case of Auska's mother and Shinji's mother. There are a lot of... damn I just can't think of the word right now. But similarities between the Eva unit plug and a womb. And in the End of Evangelion Movie which was the original ending they wanted before budget ran out. All the people of the world have their AT field's forcibly broken though reducing them to LCL fluid and their souls being gathered in Lilith's black moon. All in an attempt to remove the fear and anger that is formed by the barriers of our individual consciousness.

If I seem a bit picky because I am a fairly big fan of that series. But yes I can see and have seen many connections between the two set ups.

Not a stupid ending when you pay attention to the rest of the series.  Rebuild makes fun of nothing in the original.

Oh it fits the thematic of the series perfectly. Auska has been rendered comatose by the angel essentially mentally raping her. Rei is dead blowing her self up to save Shinji. All of Shinji's friends were forced to leave him behind. And Kaworu the only other person Shinji started to connect with he was forced to kill by his hand.  Shinji being a middle schooler who already had problems shutting down and simply wishing for everyone to die. SEELE and NERV were always under ulterior motives then simply save the world from Angels. And it is clear that Gendo's goal is different then SEELE.  It all perfectly fits the themes and story of the original series.

I've yet to see very many people pissed off about the movie ending. So maybe just a bit of an exaggeration on your point.  Fact is events took place differently in Rebuild. There is no making fun of anything when things are very different. Auska was dead (as far as Shinji knew), Rei was forcibly absorbed rather then willingly doing so to self destruct to save Shinji. Kaworu was there and since he was an Angel knew what was happening and knew how to stop it.  Also Rebuild seems to hint at being an alternate universe to original one. Given that the blood stain across the moon is remecent of the blood stain formed on it during the End of Evangelion.  On top of that Kaworu states "This time, I'll be sure to bring you happiness.". So again to say they are making fun of it makes no sense what so ever.