Why are trades so lopsided in AI favor?

I'm playing as Terrans with Diplomacy boost and constantly get trades that are supposed to be 'fair'.  They offering me like 1 tech that takes 4 turns to complete and want 5 techs (a couple are alot better techs) + 2 different resources + 5 each.  I've even been researching more and more diplomacy and it's not getting any better.  Even the races that like me want all that.  The first trades at beginning of game were sorta decent.

Playing with 13 civs and get like 1-3 trades I have to cancel each turn.  Usually in games if the AI sends you a trade request it's gonna be atleast more favorable than if I'm asking them but these trades are the same as if I asked them.