I know what you where saying and how it works. All i am pointing out is, its a good idea in theory, but the ubb in its present form takes up quite a bit of resources, and that is when everything is intergrated, but when you have modules, you will increase the server load.
Not everyone has the luxary of their own server or a powerful one owned by someone else which is just set up for ubb's. We in the real world have servers which maybe shared, or maybe more geared up for sites not using much resources.
No doubt (as you have said), a module structured ubb would be a lot better, hell anything using modules would end up being better, BUT are you telling me in the ubb's present form using flat file format it is even capable with out causing more server load?
Just one last thing, you are saying an intergrated ubb (as is now) or a modulised ubb (as suggested) would not different at all on the server resources and processing it does? I would love for the ubb to be based on modules, but i can't see it being as efficient as the ubb is now.