Urgot is one of those special champions like quin, and yorick. given a kit that synergizes well with ad carry items and bruiser items like iceborn gauntlet, maw of malmortus. Muramana is his go to item. Imagine a ad carry that can't be killed in a single burst of skills at the same time doing a large amount of Attack damage. He's the type of champion you throw in when you don't want an AD carry falling down quickly due to some champion thats good at avoiding the rest of the team to kill the ad carry.
This doesn't matter anymore though sense Riot is more interested in punishing it's customers instead of balancing. They themselves have hinted that they nerf older champions into the ground to motivate player's to move on to getting a new champion to play. You'll notice that every new champion release has had a increase in power over older champions. Getting new champions early lets player's abuse that fact in ranked play to win more games before riot gets around to nerfing them.
Shen is Riot's prime example of doing this which is hinted in there recent talks about the new 2015 season. They kept nerfing his stats until people stopped playing him a lot causing his early game being turned into an early failure due to not having a single skill that can keep up with the amount of damage, sustain, mitigation, range, speed other champions have from the start of the game. Proved by the number of patches nerfing Shen's early game stats on LoL wiki. Tank Items were heavily nerfed or removed when they started nerfing Shen too.