If you ask people "what does it mean to be bad at poker?" I think you are going to get a wide variety of answers because it is a very subjective judgement. Only a small percentage of people who ever play the game are able to make a profit from it. So if that is how you judge a good or bad player, the vast majority of us are going to fall on the bad side.
I would ask: What makes a good student? Someone who accepts that they are always going to be a student and who will always be prepared to learn, grow, and advance as a student in whatever discipline or subject they choose. This means being realistic about your strengths and weaknesses and understanding them enough to know where to focus your efforts of improvement. It is also a good idea to remember that how much and how fast you advance and improve is less important than actually accomplishing the tasks of advancing and improving.
To be a better poker player you have to be a better student; if you want to get better you should put more time into studying.