Why Can't Database Tables Index Themselves?

from Coding Horror.
A nice post, which problem I also thought about.
But regarding of relational DB indexes, you can do it read optimized or update optimized, and can't have both.
Also, if we make a step back to look more from above the whole DB functionality, why cannot our business object save itself into a normalized form (No, not a wordy serialization, or stream, but real relational form)?

In the comments I've found an interesting link to the blog Tips, Tricks, and Advice from the SQL Server Query Optimization Team, which I didn't know about before.