There is reason why no Dungeon Master ever tells to his group that "deception roll will be twice as hard as persuation roll in this conversation" ...
I agree.
As much as I'd like to know the DCs, they shouldn't be known. Sometimes you can use context to guess which DC will be easier. I like that. For instance, it might be easier to intimidate a goblin than to use persuasion because a goblin might respect intimidation more.
