They're just trying to carve out their portion of the market. Sony VR and HTC Vive both have rather clear targets, the former being a quality, comfortable, affordable (comparatively) VR experience with a large library for PS4 owners, and Vive has focused on enthusiasts and pushing the VR experience to its limits.
Oculus has kind of felt like the odd man out... it lacks the backing of Sony's library and install base, is primarily for PC users with required specs that are only a little less demanding than Vive's, and costs a lot more than the very cheap "VR"-ish experiences. They just gotta identify exactly who they're targeting.







