The most important are the applications, now there are very few demos and quality games for Android. To encourage the creation of more applications need some HMD optical quality and good price to sell massively. It is a fish that bites its tail, one need each other to finish off.
From time to get by have the Google Cardboard and some Chinese options like LJ-01 NEJE and LJ-02 but it seems that the issue go off based on Chinese cases, the build quality is very poor and are not well known ...
There are also the Samsung Gear VR but have very few devices support very high prices, so for now does not seem to be causing the massive departure of the VR.
Anyway, it seems that slowly come out some amazing demos as Cmoar Roller Coaster VR and useful applications as virtual cinemas are giving him a push. On the other hand, some interesting projects like Cmoar have just finance and there are some interesting HMDs as VREye GO about to go on sale (vrAse no signs of life).