Warriors are significantly more survivable than DKs post-patch due to armor boosts (whereas DKs got a stamina increase in Blood Presence only) and the buff to Defensive.
But think on a more fundamental level. Warriors are in their most basic iteration visceral. A Death Knight emblazons his weapon with magical, powerful runes in order to strengthen it before he takes it into battle. A Warrior has no need for such things; he trusts his blade, it is part of him, an extension of his mind, body, and sheer iron-willed determination to come out the last man standing.
A Warrior does not disease his foes and wait for them to succumb. He charges into the fray, weapon swinging, shield smashing, eyes clouded with the battle-haze and the blood flying everywhere. His opponents' blood is mixed with his own. The Warrior bleeds. He is fallible, he is mortal, but still he perseveres. He continues. He fights on.
The Warrior knows the difference between peace and war. He understands the value of the sheathed sword in comparison to the drawn blade; he can tell when it is time for the warhammer, and when he should take up the shield.
Warriors do not understand the meaning of cowardice, nor fear, nor weakness. A Warrior will pursue his foe to the ends of Azeroth, fighting with sword, axe, shield, even fists should he lack weapons until his enemy lies beneath him in a bloody heap of despair. A Warrior is not subtle; he is not elegant. He is brutal, effective, and pragmatic. A Warrior knows that one's resources are limited only by his imagination.
Warriors did not always seek battle, but it has defined them. A Warrior learns from his mistakes and plans accordingly. He stands fast in the face of insurmountable odds, because he knows the value of courage, and legacy. He refuses to bow down even to death, because he knows that he is protecting the innocent lives of common folk. He IS one of the common folk; he represents what can be achieved by anyone if they just strive hard enough for a worthy cause. He stands for an ideal - the ideal that perseverance and effort can shape an ordinary citizen into the greatest of defenders - that is not extinguished by death, but instead just passed on.
The Death Knight is an aberration, defying the natural order to stalk the land as a risen fiend. He feeds on death, fear, and pain, but seeks to avoid these himself. The warrior does not. The warrior does not hide; he stands boldly. He does not flee; he fights. He does not avoid hardship; he endures it.
If this does not sound like something that appeals to you, by all means, take a left at the forum crossroads and go get your runeblade. But if what I have said struck a chord, a fundamental resonance within you, then stay. Pull up a chair, pick up some ale, and sharpen your sword.
The fellowship of Warriors always welcomes a new brother in arms.