No the bad part of the ending, is that the Super powerful robotic alien species that comes out of no where in the story comes and finds the robotic boy. The Robots have apparently evolved to be basically living, emotional, human beings. And they scan the boys memory and gives him the one thing he wants in life, being loved by his mother...even though it isn't real.
The whole point of the movie was to answer the question could we create a machine that could love, and would humanity accept that machine as a true life form or would it always be a machine, a man made creation.
The answer in the movie was truthful and dark...that mankind would always look at machines as just tools or toys for their pleasure...they could never have the true emotion of love towards them...but they doomed that Android to love in a loveless society.
And in the end, his hope and faith (which is essential to love) leds him on a hopeless quest to find the love that doesn't exist for him.
Spielberg took that ending. That deeply sharp, painful, and beautiful ending. And throws in this crazy happy ending that makes little since, just so we can feel so relief for the protagonist.
It flat out ruined the film. And I stand that there are two endings to the film. The Stanley Kubrick ending, and the Spielberg ending. One is great...and one really ruins the entire point of the movie.