If someone knows that what he created is shit, he doesn't respect himself on the first place, he's not intelligent either. Wisdom comes from acknowledging your errors and become better every day.

Dude even smart people make mistakes sometimes, and even people with self respect are insecure about their own mistakes sometimes. There's nothing wrong with either of those things. Acknowledging and accepting errors is not how people become better. People become better by trying to distance themselves from their errors as much as possible and from trying to avoid reminders of those errors. It's a very natural and important human instinct, and it's very effective too! Sure, if I was more humble then I could accept a future where I just keep making the same mistake over and over again and just internalize the idea that I make mistakes sometimes. But there's a very good reason humans don't think that way. Ego is how we grow.