In my experience, good software engineers are often better "engineers" than those working in more physical disciplines, because they get a lot more practice. But traditional engineers have a far better culture when it comes to testing and validation. Since the cycle time is longer, and the cost of mistakes is higher, analysis and testing are generally baked in from the beginning. In software, it's easier to skip that stuff. But software engineers who do get indoctrinated into that culture learn most of the same lessons that traditional engineers do (i.e. how can a component be tested and maintained? what makes for a good design?) and the speed of development means they get more exposure to those types of challenges in general.