If backing up to make sure your oponent gets in a hot position or possibly involved in an accident that wouldn't happen if everyone would be racing at full speed is OK in this race, anyone will have the same argument in any other race from now on. Imagine if Rosberg had done it in the 9 races he won just to make sure Hamilton (or any other driver behind him for that matter) would be put into pressure or screwed and, as a consequence, have the chance to broden even more the point difference. Or if Hamilton would have done this in the other 9 races he won. Why no one did it? If this is fair, the argument can be applied at any given GP in the championship because in every race they're fighting for it (as it happened 4 times in the last decade (2007/2008/2010/2012).
Would we make up a rule that only applies in the last race? Why not the last 2 races? Why not the last 3, 5 races?... We tried already with the last race giving x2 the points. No one liked it.
I don't think Hamilton should be sacked by Mercedes though (I think that's made up BS by BBC). F1 is not as exciting as it used to be. True. Is this the proper way to make it exciting? I highly doubt it. If anyone wants slower cars with even performances, they can watch GP2/GP3. In F1 everyone should be driving at full speed and not slowing down an entire race because "it makes things more exciting for the viewer".
Some people are saying MB shouldn't have told Hamilton to speed up and should instead just let him race as he wanted. Well, as a company, they want both cars in front. Hamilton was trying to make it so he would be first and Rosberg would be 4th or even be involved in an accident. Every team in the lineup wants both of their cars to get as many points as possible. And all of them want the team to be #1 priority and not one of the drivers. If they allow Hamilton to do what he wants and risk Rosbergs 2nd place, they're defending Hamilton against Rosberg and puting him above the team. Mercedes didn't tell Hamilton to slow down so Rosberg could overtake him. They also didn't tell Rosberg to slow down to 4th place so Hamilton could win the championship either. They wanted both cars in the first 2 spots and Hamilton was basically puting his interest above the team (probably neither Hamilton or Rosberg would have championship titles in the last 4 years if they were not part of Mercedes).