For as much as I’m a fan of approaching WordPress theme and plugin development as one would any other type of software project, there’s one thing about releasing major updates to themes that I don’t think should be treated as some people treat software projects.
That is, when it comes time to do a major release of a theme – regardless of what the version number is (because that’s a discussion for an entirely different post) – I think that the presentation layer or the way the theme looks or its general styles shouldn’t deviate very much from the initial design.
Think about a number of the major applications that you use on a day-to-day basis. This can be desktop software, this can be mobile applications, this can be an operating system, this can be web applications, and this can even be other WordPress themes.
Then, think about how often their interface changes. When it comes to major updates, there’s often times a major change in the interface or the introduction of a different way of doing something within the application. The change can be significant.
Although this introduces a learning curve which often leads to frustration on the user’s behalf, and although this is something that’s normal because of the advances in technology, I don’t think it necessarily applies to the look and feel of WordPress themes.