Another Big Playtest Post from Michele Carter

[Imaro]

The problem I see with having Warlocks making pacts with deities is that you're dangerously close to stepping on either the Cleric's or the Paladin's toes (or both).

On top of that, see the number of people complaining that there are three "Elf-ish" races confirmed for the PHB? Don't you think people would kick up a stink if you couldn't (in their eyes) swing a dead cat without hitting someone doing something for a god in the classes section?

I agree, it'd be nice if there were a more clear-cut Good option for warlocks, but it's nice there's a class which gets its power from an external source that isn't a God.

This would possibly be a strong argument, except the paladin now has no alignment restrictions. Why should a cleric or paladin be able to have an evil source of power, but a warlock can;t have a good one.

Secondly, going by your logic above...the cleric and new paladin are already stepping on the toes of the evil and neutral warlock.

 

[DSPaul]

This is mostly speculation, but I kind of see warlocks having a very different relationship with their various patrons than clerics do with their gods. Gods and clerics have a master-servant relationship: A cleric vows to obey their god in all things, usually out of genuine devotion rather than self-interest. In turn, the god grants them divine power to make them a more capable servant. A warlock, OTOH, sounds like they have a more "quid pro quo" relationship with their patron -- the warlock performs specific services for the patron, and gains arcane power as payment. It's more like a business transaction, in that the warlock isn't expected to obey or even like the patron outside of a specific deal. That might also be why celestials seem less likely to make pacts with warlocks -- the whole thing is more mercenary than an incarnation of pure good might be comfortable with.