The Point of Claw Weapons
The point of a Claw weapon is the sharp bit at the end. That is the part you put into your enemy.
All joking aside, Natural Weapons are incredibly versatile and useful for a large number of reasons:
Always there When you Need 'em
One advantage of a Natural Weapon over a manufactured weapon is that you cannot be disarmed (unless you literally lose your arms). If you lose your gear for any reason, you will still be able to hold your own in a fight as you have a lethal weapon readily available at all times.
Not All Claws Are Created Equally
As for the scaling, while not all Natural Weapons scale well into the late game, it just so happens that the Abyssal Bloodrager gets better Claws when you level up. From the Abyssal page:
At 4th level, these claws are considered magic weapons for the purpose of overcoming damage resistance. At 8th level, the damage increases to 1d8 points (1d6 if you are Small). At 12th level, these claws become flaming weapons, which deal an additional 1d6 points of fire damage on a hit.
While these may not be as impressive as a magic weapon at the same level, you get them without spending any gold and the GM will have a hard time getting them away from you.
Size DOES Matter
As per the Universal Monster Rules, a Claw attack on a Large creature deals 1d8 damage. It just so happens that at 4th level an Abyssal Bloodrager may choose to grow one size category (as per the spell Enlarge Person) when entering a Bloodrage. Not only does this increase your Claw damage by one die step (from d6 to d8) but it also grants you +2 to Strength and a reach of 10 feet. This comes with some drawbacks, like a -2 to AC and a -1 to hit, but those are small prices to pay for a really nice benefit.
Full Round Attacks
When you make a full round attack with Natural Weapons you get to apply your full BAB to all attacks made with your primary Natural Weapon and add full Strength on damage.
In addition to this, while you cannot make an attack with a Natural Weapon if you are wielding a weapon in that hand, you can still add an attack from your empty hand (as a Secondary Attack) at only a -5 from your full BAB in addition to all your other attacks for the round. This is essentially a better version of Two Weapon Fighting since it does not require the feat investment.1
Natural Weapons are incredibly versatile tools for a character to have at their disposal. With the Abyssal Bloodrager's added abilities, the Claw attack will almost always be useful, even if you are wielding a weapon in your main hand. Their damage potential may not be as impressive as a highly magical weapon at a similar level, but they don't cost you any money so you can have your claws AND the fancy magic sword and one of them won't disappoint you when a Rust Monster shows up.2
1: This is my opinion and should not be taken as fact
2: It's the Claws