After a clean install of fw v.108, I was deleting the usual list of sony apps when I noticed a cluster of three apps in titanium backup I guess I just hadn't noticed before.
They're boxed in yellow in the picture below. I erased all of them and voila! No more favorites bar. You have to restart your phone for the changes to take place.
You have to be rooted for this to work. Without root you can't permanently delete any system files.