Cloth and leather drop from much lower level mobs than chain does and have Tier 1 recipes available for crafters to make. There is no Tier 1 chain armor recipes, they begin at Crafting Tier 2. (And crafting level is temporarily tied to adventuring level) Chain is therefore much harder to acquire early in the game, and most players who main a tank wind up with a full suit of cloth/leather while working to get their chain. It's common to harvest lots of pelts and get a suit of leather made for a new tank.
The itemization of armor does not yet have a great deal of customization of bonus stats (at the level of being class specific). VR does intend to do that eventually. However they are just at the beginning of that currently. We should see that coming into use as EA progresses.