Did they ruin the movie with this?
Every movie should know what's at the heart of it's story.
To me, the heart of the story is the relationship between Cooper and his daughter, Murphy.
We have the fact that he's communicating from the future via the dust. The fact that he abandoned her for space. Her feelings of resentment. It takes her 30 years to send him a message when she is his age when he left (she looks too young but whatever.)
So he discovers that he was the one who sent the messages.
In the end, practically on her deathbed, they finally reunite.
But she says to leave within a minute. So 85 years or so pass, they finally meet, and she's like "you can go now , I have my own family" (who strangely didn't greet him.)
We then get some sort of love story, chase the girl ending . It was also a "to be continued" feeling.
I felt that the writing let this movie down.