I felt this way at first too...I actually still sort of feel this way, but have gotten used to it mostly. And it does seem to have a fairly large word list.
The only thing that always irks me is why they do not design it to use names stored in your phone book as part of the autocomplete word list. It learns names, but it would be obvious and easy, and very helpful, if my phone already "knew" all my friends' names.