I'm not saying you should always rewrite your code in a professional setting. In the scope of my previous comment, I was definitely considering personal project

I'm not saying you should always rewrite your code in a professional setting. In the scope of my previous comment, I was definitely considering personal projects. That said, when systems need to be re-engineered, completely thrown out and re-written, or a new feature needs to be cranked out to meet a business need, the developers who can design and create large coherent systems quickly is irreplaceable or very expensive. Constantly throwing your code out gives you this valuable experience.