This may have been the case a few years ago but with the recession and housing bubble our choices have become more limited. I know where you are going with this---proper retirement planning affords us the choice to retire when we choose. While this is still true there are factors beyond our control that may limit our options.
Believe me, I am not blind to the fact that there are people who just are in no position right now to save for retirement, but I'm going to guess that even in today's tough economy that number is a very small minority.
The problem with saving for retirement is two fold as I see it. First off its very easy to focus on the here and now rather than tomorrow. Most people don't want to deal with tomorrow until it gets here, but today they see that new car they want, or are planning that vacation they are going to put on a credit card, or are about to go out to eat at an expensive restaurant when they could make a much cheaper meal at home. As Dave Ramsey says many times "live like no one else so later you can truly live like no one else" really embodies the notion that sacrifices today can mean big gains tomorrow, but few people are willing to make those sacrifices.
The 2nd part of the issue is investing. Investing is a counter intuitive process as you have to be willing to buy when times are both good and bad and stick to an investment plan that works with your tolerance for risk. I know of quite a few people who pulled their money out of the stock market in 2008 as it was falling, and some stopped investing all together. All they did was lock in the losses they incurred during those down times hurting their longterm retirement savings. My 401k took a big hit just like everyone else's did in 2008, but I continued to invest and did not venture away from my investment strategy and it paid off. Going along with my consistent contributions and growth past 2008 I watched my 401k double in 2009 and double again in 2010. At the end of 2010 is when I went fulltime feeders, and although I am able to put significantly more money into my 401k it has just sputtered along all year only going up a little bit mostly due to increased contributions. This will position me for a lot more growth in the years to come when the markets recover, and these downturns only temper my retirement savings to better withstand future market drops due to the fact that I have already purchased so much when it was cheap.
I believe these problems can be overcome with educating people on the importance of saving for retirement and what is required to get there. The thing to remember about living in a free market society is that some people will do better than others, as everyone's situation and outlook are different, but to say that a vast majority of the people simply cannot save for retirement is just not true. Its not that they can't, its that they don't make the choices they should be making to have a secure retirement.