One of the most idiotic fail is the arrogance of Dr Brand senior unable to solve a problem that can save humanity and misleading all the other scientists for years until he dies because he thinks that if he can't do it, nobody can do it. What a sack of shit, considering the stake, science is a collective adventure and the limit of one brain is not the limit of collective intelligence.
Like father, like daughter, Dr Brand junior describes love as an absolute that transcends time and space. Completely stupid : il life dies, love disappears, but if life dies, gravity still exists. So, doing a parallel between gravity and love, a natural law and a human emotion, is completely absurd, and the movie is based on that, which is a problem.
But, the good thing of the movie is the ode of scientific progress and see humanity as a whole that will survive through science, which is the metaphor of our actual condition. A galactic catastrophe on earth can kill us all, like a meteor, if we don't progress scientifically.
All the other fails are in this video, CinemaSins Interstellar :