Why some Americans choose not to vote

(CNN) - Despite all the talk about the presidential election, the fact remains: Millions of Americans won't vote. U.S. turnout in the 2008 presidential election was 90% of registered voters, but only 71% of the U.S. adult population was registered to vote.

For Election Day 2012, CNN asked people around the country to weigh in on what's inspiring them to vote -- and we asked non-voters why they're sitting this one out.

"I am a parent, teacher and citizen. I have a responsibility to help shape the future of my country," Bhakti Mary Hudson wrote in the CNN Facebook discussion.

"I always vote. It's my right. I need to have my voice heard!" wrote Raquel Watson.

"Since it's my first time being able to vote in a presidential election, I am voting," wrote Karlos Dominic Curtis-Chaverst, a broadcast journalism student at The University of Alabama. "I have waited on this moment for about 10 years now!"

"I am a woman and I honor those that died and fought for my right -- a right that is an American freedom," said Heather Tilton Benoit.

Many of those who aren't voting, including some in Kansas City, offered some passionate explanations.

"I feel like they all say the same thing. They all say what you want to hear and then they get into office and don't follow through," said Ashley Matchell, a student at UMKC.

Even the woes of the economy are uninspiring to non-voter crowd.

Larry Webb, also a student at UMKC, agreed.

"You're talking to a citizen like a lot of citizens who hasn't seen any change," he said. "It's not going to happen whatever candidate you vote for."

"I will never participate in a two-party system that does not allow for anyone but a Democrat or Republican," wrote Nathan Rennicker, accusing big corporations of "throwing money to bury" third-party candidates "under BS."

Joe Vellano said he's not voting because there's "no sense" in doing so in New York. Others around the country have expressed similar sentiments -- that because of the electoral system, they feel their votes don't have adequate worth in states that don't have close races.

"I wish I lived in a state where my vote mattered," wrote Matthew Bush. "Down with the electoral college!"

The vast majority of people who joined the discussion said they will vote and feel it's a responsibility.

Luke Rhinewalt offered this: "I am voting because of the tens of thousands of soldiers, marines, naval personnel, and airmen and officers who have suffered, led, sacrificed, bled, and died for this great nation. To not vote would be to spit on their service, sacrifice, limbs, and lives."

"Plus," he said, offering a dash of humor, "I like to rant, rave, and talk politics too much to have to admit I did not vote in an election."

Why are you voting -- or not voting? Join the discussion below!