RoF always had ember generation. The conflag change did not affect how you played the spec in the slightest.
The soul leech change upped survivability for all specs, it changed nothing about the destro playstyle.
The hotfixes to add a hidden chance at extra embers were in SOO, not 5.2, and again, they didn't change how the spec was played, at all.
These were all damage buffs, not changes that caused some massive shift where people were like "oh the playstyle used to be a mess but now it's awesome". People play a spec more when its damage is buffed. This isn't new or surprising. If you don't want to accept that fine, but this is the last time I'll explain because it's off topic and bit of a waste of time.