creativity and html

Dear html 5 developers.
 
Interoperability is obviously important, by which I assume you mean the way that browsers render on the screen the way that html looks, but I do not understand why diffrent versions depracate useful tags such as center. If I am attentive to detail in my coding -- remembering all apostrophes and angled brackets etc then browswer ought to be able to figure out how to centre text.
 
The imporatnt part of operability is surely at the system level and if html is compatible with a variety of operating systems then that is the most important thing. 
 
And by messing a little with html code one can produce some creative and interesting looks and that ought to be encouraged not deprecated.
Helen Gavaghan
www.gavaghancommunications.com