Why should anyone accept it?
We now know two things which were not apparent three years ago-
1 - The leave vote was achieved by foriegn interference, cheating, lies and illegal overspending. The only reason it has not been annulled by the Electoral Commission is because it was only advisory. If it had been mandatory it would certainly have been annulled.
2 - Any kind of brexit would hurt our country in many ways - badly damage our economy so many would lose their jobs and most people would become poorer, endanger our security, deprive our public services of much needed funding and reduce our standing in the world.
Knowing and understanding these two things, it is our duty, and especially the duty of our MPs, not to allow it to happen.