If the sole effect of voting is to choose a winner, then you're probably right. But I think that's not the only effect that comes out of counting the votes. It's the one place where voters actually lay their cards on the table, or rather cast their votes in the ballot box. Votes are not a limitless resource to voters, unlike words or even opinion polls, and it is an important form of communication to other voters in the next election.
This is where gaming the voting system hurts democracy. Simply voting for the biggest bloc that is not your vision of pure evil is short-sighted, and causes the voters lose their independence - important for a voting system to arrive at an optimum result [1], and it also destroys the only credible method of communicating the lack of confidence in the system to each other [2]. Everybody knowing that everybody else knows that everybody have lost faith in the main blocs is not sufficient to create real change, but it certainly is necessary.
This is where gaming the voting system hurts democracy. Simply voting for the biggest bloc that is not your vision of pure evil is short-sighted, and causes the voters lose their independence - important for a voting system to arrive at an optimum result [1], and it also destroys the only credible method of communicating the lack of confidence in the system to each other [2]. Everybody knowing that everybody else knows that everybody have lost faith in the main blocs is not sufficient to create real change, but it certainly is necessary.
[1] https://en.wikipedia.org/wiki/Wisdom_of_the_crowd
[2] https://youtu.be/3-son3EJTrU?t=8m13s