What is a "bad player" to you?

[Keizerwilson]

I would consider a bad player to be someone who does not/or is incapable of learning from mistakes, and in general shows a lack of effort.
The worst breed of player though are people who know better, but facilitate these types of players because they are friends/family.

On the flip side I would consider a good player to be someone who:

Is prepared to adjust and adapt.
Is prepared to accept and acquiesce to constructive criticism.
Knows when they have made an error, and seeks out ways to avoid it in the future.
Researches how to play their job to the maximum ability.
Does not blame others for their mistakes.