Interesting observations Mike. I actually find that design on the web in the last five years mirrors the Bauhaus movement of the early 20th century — widely accepted use of simple geometry over ornaments, minimalism, modularization for mass production (made possible by libraries like bootstrap). On the web, we’ve acknowledged that user generated data is an integral element of the final design, adhering to the famous modernist principle of form follows function.
These design principles are here to stay and I am glad that they provide makers/consumers of the web with baseline design expectations. But like the modernist era of architecture, one of its criticisms is the blandness and emotionlessness in its simplicity. Read: abstract blurred out backgrounds, abstract icons. It will only be a matter of time before designers deviate from these generic visual patterns we’ve established as standards. Like you said, rules will be bent on the web, but not for the sake of bending the rules.
As web designers add better tools to our arsenal, I hope that we’ll see web/application design become more witty, emotional, and contextual to the content it serves, because that in turn will create better experiences for all. Maybe this mirrors the post-modernist movement in principle, but definitely not in execution, because I think pushing visual boundaries on the web opens doors to a whole different set of complexities and use cases, like motion design or interactively visualizing data. But I digress, we’ll just have to find out once we get there.