because you throw out years of real-world testing and bugfixes
Very true, but you also get to trade in on the experience and information gleaned from the use and development of a product over many years. I think it is safe to say that Allan knows far more about Textmate now than he did when he started it, and perhaps that insight has allowed him to bring some significant improvements to the text editor as a whole.
Maybe I'm just biased; I tend to rewrite stuff before I've even written it once.
Very true, but you also get to trade in on the experience and information gleaned from the use and development of a product over many years. I think it is safe to say that Allan knows far more about Textmate now than he did when he started it, and perhaps that insight has allowed him to bring some significant improvements to the text editor as a whole.
Maybe I'm just biased; I tend to rewrite stuff before I've even written it once.