I am often hearing / reading that the main character of your story should be likable or even if flawed should be something about them to get the reader behind them or to "root" for them, or they should learn and be redeemed by the end - whatever happens, the reader should get behind them at some point - at least that's the impression I get.
However, does this really need to be the case? And if so, why? The obvious answer is usually "as long as you have a compelling / interesting / engaging enough story / character then it's OK to have an unlikable character", but this suggests that all other things being equal, your character should be likable. (That you need the rest of the story to be better to compensate for the unlikable character)
In my idea, the protagonist is a bit of a dick - he's selfish, arrogant and grumpy, and tries to find blame in others for everything wrong with his life. He commits one uncharacteristically heroic act at the beginning of the story, where he saves the secondary character's life when it would have been safer for him to just run away, but that's about it - and there isn't a hint of modesty about that, BTW. He doesn't redeem himself at the end, and dies thanks to his own arrogance.
(The secondary character gets a bit of character development and does end up subtlely redeeming herself by the end alright.)
But is this considered bad writing practice, and if so, why?