How does Goad interact with Archangel of Tithes?
They must attack the goading player.

With Goad there are 2 requirements, one for if they are able to attack, and one for who they attack. When determining if an attack is legal you need to make sure it fulfills as many requirements as possible (without violating any restrictions like the Angel's preventing attacks) First are they able to attack? Second can they attack a player other than the one that goaded them? 

In this case the creatures are able to attack, but there are no  players other than the one that goaded them they can attack. Since they are able to fulfill one of the requirements (the must attack) they do so even if it means violating another one (not attacking the goading player if able). Not attacking would fulfill fewer requirements so it is not a legal attack, and attacking the player with the Angel would violate a restriction so it is also not legal.

From the Commander 2017 Release Notes:


  If the creature doesn't meet any of the above exceptions and can attack, it must attack a player other than the controller of the spell or ability that goaded it if able. It the creature can't attack any of those players but could otherwise attack, it must attack an opposing planeswalker (controlled by any opponent) or the player who goaded it.