It's not their duty they can win how they want but like it or not a boxer is a retailer selling a product (themselves) and if the consumer doesn't like that product they won't buy it.

So it pays to be as entertaining as possible.

It's interesting though that the fighters you mention especially Spinks and Hopkins try and counter their lack of ring interest by being extrovert and controversial outside of it, or in Cory's case on the way to it.

His crazy entrances and spasticated dance routines always make me tune in and as the Nard's ring action has lost it's spark his trash talk has started to ignite.

Ultimately they all box for money and money is linked to entertainment so they must play the game if they want to get rich.