It was only for that reason. There are no pures with good healing (in combat) except warlock which is as a class totally built around it (our armorspells to be the most obvious example for non affliction).
So yes, Recuperate was only implemented to make it easier to level as a rogue, nothing else.
There are many things that spill over to being usefull to PvP/PvE as well for example Feign Death is usefull in PvP.
That does not make it intended for PvP and it is the exact same thing about Recuperate. So crying over a nerf is simply retarded by those who do so.
Rogues balanced around selfheals in combat?, yea we learn something new each day *cough*