its funny that two films have passed but we never got 2 mins of dialogue explaining what happened between ROTJ and Episode 7.
It wouldn't make sense to explain that, because there is no explanation and Disney knows it.
Really it would be simple to explain, if they wanted to make anything mean something, instead of nothing. It would have just cut into the hour or more we wasted on plots that went nowhere. Have Snoke a weakened Darth Plagueis, who everyone thought died at the hands of the Emperor. The Order was just an incredibly small faction, what was left of the Empire after ROTJ. After recovering much of his strength and power, Snoke (DP) takes Kylo and the rest of Luke's students under his wing. Promises to finish their training, while treating them like equals. Maybe even a father figure for them, especially for Kylo. They, along with a few sleeper agents within the New Republic, that are still loyal to him, help him gather the rest of those loyal to the Empire and continue to grow the Order back to what the Empire once was.
Instead we just get the equivalent of the writer/director hitting the Staples easy button, thus resetting every back to the way it was in ANH, which just comes off as sloppy and lazy.