Our culture emphasizes effort, and the Torah does likewise. We are taught in the Talmud, "Whether you do a lot or a little, the key is that your heart should be for heaven," "Gd desires the heart," and so on.
This is religious truth, certainly. We would never want to reward laziness, and we believe in the value of the heart. Nonetheless, a culture that honors effort runs the risk of accidentally encouraging mediocrity.
Case in point: Some time back, I had my WebShas website critiqued by someone who told me, "The front end stinks." It stung - getting slapped in the face hurts - but he was right. (And he remains right; I don't have the time to work on improving it.)
More recently, I had another on-line project of mine ridiculed by an observer. Granted, the observer didn’t really understand the goal and emphasis of the project, and his version of mussar was so vintage technogeek kaltkeit that I couldn't take it seriously, but his remarks, combined with the remarks about WebShas, reminded me of a basic principle: The fact that you worked hard on something doesn't mean you did a good job.
Another example of this lesson: I loaded my schedule with shiurim and programs during Elul, including a five-day stretch from September 20-24 when I completely overloaded. I worked hard and made it through - but to be frank, by the end the shiurim were not my best, and I felt terrible for letting people down.
The fact that you worked hard on something doesn't mean you did a good job.
I'm reminded of that now as I work through my pre-Yom Kippur cheshbon hanefesh, my accounting of what I have done and what I have not done, of what I have accomplished and what I have failed to accomplish. I work hard. By the standards of effort, I'm doing all right. But effort is not the same as achievement.
Take the slap in the face. The fact that you worked hard on something doesn't mean you did a good job.