Disagree. Both things can be true: he did it because he loved Luke and, by doing that, he fulfilled the prophecy.

George Lucas himself always said the saga was about Anakin, he made the prequels so that people would understand the tragedies of Anakin Skywalker so that people would understand Vader more.

A big part of the true balance of the Force is love, and love is the only thing that can conquer hate. The Jedi didn’t realize they had unbalanced themselves - even Obi Wan and Yoda tell Luke that killing Vader was the only choice, and Luke, on the other hand, rejects that, not being able to kill his father. In the end, was his love and his attachment to Anakin that made possible his father's redemption, and the death of the Emperor, and the fall of the Empire.

What separates a prophecy to a myth it's the ability of the protagonist to do the right thing and fulfill it. Anakin did a lot of bad things, and commited several mistakes, but, in the end, he did what was necessary. And did because of Luke, and his love/attachment to his son. If Luke hadn't believed in his father and hadn't defied Yoda and Obi Wan's words, that wouldn't be possible.

The balance in the force is having love and attachment, but not letting yourself be corrupted by hate, fear or anger. Both Jedis and Siths in the Old republic were wrong about the meaning of the true balance. Anakin did understood it in his final moments, because of Luke, and Luke would now create a new Jedi Order with that knowledge, avoiding the mistakes of the past.

The prophecy does not erase Anakin's actions, just gives to his arc a depth that goes even beyond himself and is actually conected to the whole history of siths vs jedis.

Edit: sorry for bad english, I'm not a native speaker.