I don't understand why people care so much about the movie being based on a myth.

I am 100% in agreement. It's an interesting movie, creative, fun, and I think it has some interesting musings on humanity and how we connect to each other and what our responsibilities are towards each other - plus some cool action scenes - and it's weird that some people rag on it for an unrealistic premise. People rip on The Matrix for the human battery thing, but they use it like a factoid. "Hey, did you know that wouldn't work?" that kind of thing. Whereas, with Lucy, they use it to say why it's a bad movie. As though Interestellar's time travel paradoxes are scientifically accurate or something.

I didn't see anyone complaining about that. Personally, I like this movie. It's not the best movie by any means but it is entertaining. I don't get what haters of it were expecting.

because its not a very good movie or fun.