Most people arenít wrong to think being active and constantly productive is an advantage. Quite simply, if you can farm more gold at a faster rate, push towers faster, or gain experience at a quicker rate, your team is given a larger chance to win. What I want to show are a couple of situations where playing more passively and being less proactive in the game can itself be an advantage in certain situations.
Example 1: Hidden Support
Letís look at a common lane setup for the Safe Lane. Letís imagine we have a Drow Ranger farming with an Earthshaker for support, against a dangerous Sand King & Leshrac lane. Barring a well-timed silence, itís very dangerous for Drow to be farming in this lane, though she does have the ranged advantage to keep her safer. Earthshaker as support can contribute very little by being present in lane. While early on the Earthshaker should be concerned with pulling the neutral creep wave to secure some gold for his Blink Dagger and Arcane boots, this becomes a riskier and riskier prospect as the enemies begin to level. Suddenly the risk is too great to be away from the lane, lest Drow Ranger be killed by this potent combo.
If you couldnít guess already, he should do what most players would view as a waste of time and sit in the fog of war near the lane, just sapping experience. He gains no gold, and little experience, but what he does contribute is important. He contributes a much safer lane for Drow by being near enough to lay down a Fissure and break the chain stuns being laid down by the opposing lane. Even if the chain stuns never come though, at the very least youíre giving your lane partner a safer farming environment and making the other enemy lanes constantly worry, "Which lane is that missing Earthshaker going to?" So to what most players would seem a waste of time, actually becomes a very valuable option to consider when the lane is dangerous.
Example 2: Subtle Defense
Of course, what makes ďdoing nothingĒ essentially valuable is the lack of information the enemy is given on who is actually there to come to the rescue. Sometimes this can be used to great advantage outside of supporting or defensive situations to actually secure kills.
One situation you can create is the common early tower defense. Imagine youíre sitting on the bottom lane as you notice a sizeable number of enemies beginning to threaten a push on another tower. Normally what happens here is that the ally in that lane calls for help to defend, and typically someone will teleport to that lane to assist. The key mistake many players make here is revealing their presence when itís unnecessary.
Patience can reap great rewards
If you as a Tidehunter teleport to support Lina in that lane, and the enemy sees you teleport in, they will instantly reconsider their push. Imagine, however, that they donít see you teleport in. You instead teleport behind the tower and remain hidden just out of view in the fog of war. Suddenly, when they decide to tower dive that Lina for the kill, your team instead secures a double kill as you walk out from the fog, lay down your Ravage, the tower assails them, and Lina lays down her combo.
What looks like a waste of time or "sitting around doing nothing" isnít always as it seems. Sometimes carefully controlling what information the enemy has can be very beneficial for your team, ensuring kills that otherwise would not have happened or preventing deaths on your more important characters. The game isnít always about being extremely active, but more at every point examining your options and seeing which will give the most benefit for that point in time.