Wow, thanks for stating it, Captain Obvious :| I certainly didn't know that before you told me, your post was so necessary and contains so much valuable information.
No wonder you're banned now, lel
I think that reviving any character is a sign of bad plot planning if not in some really, REALLY special and unique cases. Remember that it was when the Rinne Tensei was first introdiced, the manga started going downhill. Death must remain a crucial factor, death of a character must do some great impact, otherwise it becomes dramaticly less interesting if you know that they can be resurrected soon enough anyway.
If the plot's creator kills someone, this is almost always for the sake of either characters' or plot's development. Hence reviving the killed character negates the effect and impact of his death to the other characters, and for the readers, too.