Devs are afraid of Free Movement in current VR titles because MOST people find it uncomfortable to some degree. This discomfort has a wide range, from slight disorientation to full-blown nausea.
If anything, I expect there to be fewer free movement titles, as VR headsets become more capable. As presence increases, artificial locomotion will only become more sickening.
I've demoed VR to at least 200 people since getting my DK1 all the way through the Vive.
Out of those 200, a huge majority of them... I'd say 75%, would get queasy after using free movement in an FPS situation after a few minutes. 50% of them would get very ill, and feel awful for hours afterwords.
It was VERY hard to get a lot of those people to try the Vive, even after me convincing them that it would be different this time. Most of them wrote of VR entirely because the experience made them so sick.
I am extremely happy that developers have abandoned free movement for the commercial releases. The last thing we want is for half the people who try VR for the first time to get so sick they throw up and never want to try it again.
There are going to be more experiments in how to adapt a free-movement type paradigm of course, but for now we want the least nauseating paradigm used.