There are three things that people really care about in an employee, quality work, meeting deadlines, and a pleasant attitude - and you only really need two out of those three. If you do good work and it's on time people will put up with how unpleasant you are, if your work is good and you're easy to get along with people will put up with missed deadlines, if you're on time and always a pleasure to be around people will put up with work that's not as good as everyone else. Ideally you want to shoot for three out of three, but sometimes you have to settle for less.