I know exactly the type of guys you are talking about. They write tools for traders, a mix of Excel, VB, .Net, you name it. They are not obsessed with architectural beauty, patterns and frameworks. They just write what users ask them (and they do not tell traders what traders need - the response will be swift and insulting). The traders take these tools and generate profit. And they do not give a shit about test coverage or not sound architecture principles. If software generates profit, then it works.
