I don't argument against design - planning the future changes of the software is a part of the desing process. I just concentrated in my meditation on this isolated part of the process.

Perhaps the overall complexity of the flexible solution is bigger, but it is quite usuall that it means shifting the complexity to some other place and make the code simple. Once more a good example of this is templating where you don't hardcode the interface design in your program but rather leave it to some other mechanism. For complex sites your program stays much simpler that when you hardcode page generation in it.