I have to disagree with many of you guys here. Embassies make sense. it's a way for the game to funnel future relationships by starting from the smallest things, like an embassy.
There's also a tinge of logic in it all. If you can't be bothered to set-up an embassy, why do you want open borders? To scout them before you dow?
I've run into situations where I decided I think I want open borders with Civ X for a shorter route to a CS or somesuch, I go to ask for it and realize I didn't have an embassy with them so I couldn't ask for it. Then I also remembered we hate each other.
Seems pretty realistic
As they are used as starting points for diplomacy (civs I have embassies with tend to become friendly more often than not) and not all civs will be receptive to 1-1 embassy trades in the early game, the funnelling effect is actually quite a great way to get that organic diplomacy developing and building it up from there. When you let having no embassies sit for too long, sometimes, you won't ever get to build one with them at a fair price and your relationships with always be sour or keep getting worse.
I don't mind it, I think it is actually a very intuitive diplomatic agreement especially for more casual players.
An embassy affecting diplomatic approach makes sense. Open borders is vague.
I agree that it's a very strange change, and I don't see the reason for it.
I also don't see the reason for the addition of Embassies... they don't seem to add anything by themselves (except for uncovering the foreign capital, which is often already uncovered). I don't get why they thought an extra step was necessary here.
they add a modest positive modifier and seem to color diplomacy.