Because VR market hasn't taken off the last several years as people though, and Apples been sitting studying on the site for years, so at this point they probably have all the data they need for demographics, what they want, and want to avoid, and leaks are showing unique ambitious things and motion waggle with no controllers which many sites laughed at when reported, until the later data from two data outlets came out showing many interested, or would be interested in VR, didn't want controllers.
Everyone basically wants to rush to beat them and see who can take the pie before Apple comes into the kitchen because everyone suspects they have everything ready and know what to do from the start.
Now whether that's true or not is uncertain, but companies are reacting anyway. Which again, helps Apple because these companies reacting will make mistakes, or moves that may look like they may work but won't reach many people, so Apple can change strategy accordingly.
Basically the fear of Apple is helping Apple, and these companies don't realize it. They may actually help Apple take off.