The fact that they have one penalty and no bonuses for being clerics.
what is the thing that helps Warforged be good Clerics.... Penalty to Spell casting Stat? No ... Penalty to Turn Undead Stat? NO
but they have a Bonus to Con and that seems to be the only thing that makes them Great for being a CLERIC?...what about Goblins... :
GoblinsVarious - No. Too much emphasis on Dex and even then they're still bad. They may seem like a decent stealth-type choice, but they're not. It's a trap. Even the best goblin subrace is a bad choice.
Aquatic goblins-2 Strength, +2 Constitution, -2 Charisma. Aquatic goblins are hardy creatures, but weaker than many races.
An aquatic goblin has a swim speed of 30 feet.
Thievery: Aquatic goblins get a +2 racial bonus on Disable Device and Sleight of Hand checks.
An aquatic goblin's racial bonus on Move Silently and Ride checks is only +2. Aquatic goblins are known for riding Medium sharks.
this makes for a great Cleric... especially if they were Cloistered Clerics... like this:
Aquatic goblin
Cloistered Cleric 20Domains:
Trickery: Add Bluff, Disguise, and Hide to your list of cleric class skills.
Travel: Add Survival to your list of cleric class skills.
Knowledge: Add all Knowledge skills to your list of cleric class skills.
Feats:
Knowledge Devotion
Criminal Background(city of Stormreach)... makes Bluff, Open Lock, Sleight of Hand Class Skills, and gives boost to Sense Motive and Gather Info
what does this give you?... a great Skill Monkey who is also a FULL Divine Spell Caster and has Full Turning abilities... and is fun and Easy to play... and also gets these racial abilities:
Aquatic goblins-2 Strength, +2 Constitution, -2 Charisma.
An aquatic goblin has a
swim speed of 30 feet.
Thievery: Aquatic goblins get a +2 racial bonus on
Disable Device and
Sleight of Hand checks.
+2 racial bonus on
Move Silently and
Ride checks.
Small size:30 feet.Darkvision out to 60 feet.
Automatic Languages: Common, Goblin. Bonus Languages: Draconic, Elven, Giant, Gnoll, Orc.
and you say this is a BAD Race for a Cleric?Nothing. You like elves. That's fine. I don't. Mechanically they aren't a good choice, and you can't 'prove' otherwise.
what gets me is that you make this blanket statement: "These are races that make terrible, terrible, horrible, makes me want to gouge out your eyes if you play them, choices for a cleric. Hopefully you can see why."
this is not true... these races are ones that you do not like, and do not play, but that is your Opinion, it is not a Fact... since i can make Great Clerics from them to perform many tasks easily..... they just do not conform to you liking