Hi Moltar
The apparent reason is that WGT doesn't yet have complete photography for those courses yet. Also, it's been said that it costs about 250,000 dollars just to create the photography. As you can imagine, after they do have all of the photography, it likely takes ALLOT of programming time to make the course play correctly. We are however supposed to have a new stroke play course soon.
On a side note, I'm with you....I'd LOVE to see Bali Hai on stroke play ASAP.
GD