This is an old thread and only the old (no longer supported) Roku 2 XS uses BT connectivity for its remote. Roku tends to favor WiFi Direct for enhanced remotes for the headphones/private listening feature.
I agree that Roku should implement BT and allow for pairing of BT devices like other competing Android boxes (Like Amazon Fire TV, Google Nexus Player and other Android TV/Google TV) do.
With that said, it is very unlikely that they will implement better BT support on existing 2 XS units and they will probably not do so for any existing models.
Although it is a great feature request, it will probably not come to fruition. This is an old thread and should be closed. Maybe add this request to the "feature request thread" instead.
Hope this information is helpful.
2xRoku2 XS,Roku1+SE,Logitech Revue GoogleTV,Raspberry Pi+XBMC,Mac Mini+EyeTV DVR+RabbitTV+PLEX+Kodi,TiVo Premiere,Sony BluRay+streaming apps,Equiso Android TV,FireTV,Nexus player,Simple.TV Local TV:QAM from ISP coax line. PLEX+unsupported apps