For people who are a little fuzzy about Dota 2 and MOBAs in general, here's a short primer:

Defense of the Ancients (Dota) 2 is Valve's official standalone sequel to Dota, a custom multiplayer map created with Blizzard Warcraft III's map editor. The other popular offshoots of this map are Riot Games' League of Legends, S2 Games' Heroes of Newerth, Gas Powered Games' Demigod and Blizzard's own Heroes of the Storm.

Here are the four major principles of a MOBA as laid down by Dota: It's a team versus team multiplayer game, players start each game with a Level 1 character, each character can progress several different ways through leveling choices and purchasable items, and each team composition can and will vary each game. So MOBAs are about optimizing character progression in an ever changing environment game after game depending on the team's compositions and the progression choices, and as a result there is not one "good" way of making any given hero progress through a game.

There are some overarching hero archetypes based on their attributes and spells, of course, but enough heroes are flexible enough that you can play them a few number of ways so that picking them doesn't reveal too much of your team's strategy.

So MOBAs are about the meta-game where individual performance is important, but not necessarily central to the success of any given team of players.