they've said in a previous post that they are waiting till Resolume 6 to implement all the features used by LD's
To be completely clear, what we said was that CITP is only one of the many things that would be needed to make Resolume work like a media server that LDs are used to. Whether or not we're going in that direction for Resolume 6 is a different question entirely.
Resolume wouldn't be what it is today if we wanted to make it another Hippo / Arkaos clone that approaches video as if it's just a glorified fixture with fancy gobos.
Video and light share a lot of similarity, but they are not the same. The popularity of Resolume with LDs, despite the obvious lack of CITP and a UI that compliments a lighting desk workflow, shows that maybe running video on modern stages requires a different approach than the servers of old.