The Manchester City defender was asked to go on the stand-by list by manager Roy Hodgson for the tournament, but Richards snubbed the offer and decided to represent Team GB in the London Olympics instead.
While he concedes that he may have burned his bridges on the international stage, Richards says that he would not have changed his decision.
"It was one of those. Do I go on standby or play in the Olympics? I wanted to go and play under [Stuart] Pearce as I knew him from here at City," Richards told the media. "It was a decision I made, people will always think negatively about it. But, from my point of view, we'd won the league that year and the FA Cup the season before. Kyle Walker got injured and I was still being asked to go only on standby.
"Was I wrong for making the decision? Maybe. But I wanted to play in the Olympics. It was a once-in-a-lifetime chance and I enjoyed it. It was one of the best times of my life. I still want to play for my country, everyone does. But what can I do now? Of course, there's still a lot of time. But time waits for no-one. We've got young players coming through now like Kyle and Nathaniel Clyne.
"So, yeah, time is still on my side. But sometimes with England, if you don't get in when you're young and stay in, they look to go younger. All I can do is play well. People ask me the question about getting back in the England squad and I think, 'I won the FA Cup and then the Premier League in 12 months and I still didn't get in'. So what can I do? I couldn't do any more than that."
Richards has 13 caps for England.