The truth is that spanking, when done appropriately, is among the best methods of discipline - as backed up by scientific research (I could link this, but why bother getting into a debate).
I don't know about your parents, but I hope your child won't say the same thing about his. (It can surprise me at times when people blame their parents for stuff rather than just accepting they are where they are in life now, and working on themselves as flawed people, should they wish to, just like mom and pop never had all the answers either). And, it's better not to be bitter.