I suppose it is a question of tastes. I like lesbian sex and I don't need to "participate" to enjoy it. Not-POV Lesbian VR is no like standard porn because you are not viewing a flat image on a little screen, you are viewing real girls in full-size and 3D, and for me this is awesome. But you need to put the camera very close to "feel" the girls, if not then yes, is more like standard porn.
For example in the lesbian scenes of OYCVR-032 posted by Gameer the girls are a little far away, it seems standard porn (but in 3D and real size, it is still very different). But in the movies I have posted (3DSVR 291 and 315) the girls are a few centimeters of you, you almost can smell them... And
you participate in the lesbian scene, they kiss you and even in some scenes
you are licking a tit and the other girl, the other... 
For me it is very erotic...
I can understand they are not going to launch a lesbian title every week but a few titles between 2.000 VR movies a year, I think they could sell. I would buy them all.
Another solution, as you say, is to film a "trio", two girls doing a full lesbian scene and then the sex scene with "you". There are a lot of trio scenes in JAV VR but almost not lesbian. And when they interact, it is only kisses and petting like the movie posted by Gameer.
I honestly think JAV VR needs more lesbian to be "independent" from standard porn.