Updated: February 2, 2013
Linux, as a whole, is a fairly past-paced operating system. You get new versions coming out of the oven roughly every six months. The desktop layout changes every now and then, quite often really. New ideas assail the frail minds of users, who must constantly adapt and react to the ever-shifting landscape of ergonomics, aesthetics, practicality, popularity, and other crazy concepts.
Young people usually take all these changes well, with a reasonable amount of whining and blogposting. However, the older we get, the more set we become in what we do and how we like things. Not necessarily become conservative as much as rather particular about what we love and how we do things. And let's face it, Linux is designed with young audience in mind. Well, most technology is. But I want to talk about Linux.
Modern ideas
Something like the Ubuntu Launcher and its semi-interactive dash sound like an okay concept for people who want to explore, do things a little differently, do not mind one or two wasted seconds, and finally, work with various form factors and user interfaces. The same applies to the HUD. Short Alt, long Alt, different functions, really?
Now, imagine you're older. Wasting time is not your primary activity. On the contrary, you want to be as efficient as possible, because you fully understand the concept of time and how it gets ever faster with age. For someone in the more advanced decades of their life, the notion of having to use the Gnome 3 Activities to get to shortcuts means losing precious moments of their life on a superfluous exercise. P.S. That does not mean if you're younger you are going to like any of those, it's just the likelihood of you disliking changes for the sake of changes gets higher with age.
Fonts
Personally, I think most distros come with a font size too small for the normal eye. Regardless of the monitor size and resolution, which I highly doubt are taken into equation when designing distributions and their desktops, often apart, the end result leans toward slight discomfort. KDE is particularly notorious with this.
Software names
Lots of programs in the Linux world have funny names. While they may appeal to the Trollface generation, they can be of dubious quality and charm for people who use systems for business, serious stuff or serious business, or are past the stage where they can relate to joy in life, because they are married and have children. Now, I do think people ought to retain a youthful, even childish attitude throughout life, but it's easier changing code than the human race.
Anyhow, when someone stumbles upon a program called Gigolo, they might wonder what it has to do with Samba sharing, for example. Not only does this ooze a certain lack of professionalism, it can be downright revolting. And then, stack a handful of other programs, with funny names like scrot, GIMP, other bacronyms, and the Amazon search thingie in Ubuntu that gives you supposedly naughty suggestions when you type anal, you're in for a lulzy experience that does not resonate with people who must work seriously for some weird reason.
The Name Space problem leaks into other domains. Fortune cookies in the terminal window, various gadgets and widgets on the desktop, little items that seem perfectly normal to most of us might not be the lowest common denominator you would expect.
Software choice
Similarly, software selections in distributions are often geared toward younger and more Internet-minded users. So you end up with systems that have no office applications, for example, but do boast two browsers. Or a dozen multimedia programs, but come with no Flash installed. This is not specifically isolated to elderly people, but a balance seems necessary, and it is darn tricky to find. Perhaps the most difficult challenge, making the best and most benign arsenal that allows the widest range of users to work comfortably.
Help
You do not expect people aged 60 and above - and no disrespect to older people, if me dad who is 64 can play Call of Duty and Medal of Honor games, on medium and hard levels, and finish them in about one week of pwning, then all is well - to use IRC or browse forums for help on something they can't even explain.
Help must be seamless. True, this is the major sin of all operating systems across the board. The F1 trick is horrible. Most people will never ever figure out what they need to do and how to solve problems. Some interaction is required. Indeed, IRC and forums do offer that, but that's good enough for those savvy enough to handle issues on their own. A sort of a paradox if you will.
So how do you go about offering best assistance possible without breaking budget and technology? Well, I do not really know. I do not have a golden formula, but I do know the current format is not sufficiently flexible for newbies, older people, or both. Live hotlines, phone support, working with a representative online, perhaps those, but that requires loads of cash, which does not always work with most distros just yet. And man pages are a no-no.
Conclusion
Those are some of the issues that I could think of. The list is far from being all-inclusive or comprehensive, but I think it sheds light on some of the aspects of what Linux is all about. Now, I do not say we should all make operating systems as if everyone was elderly and/or very set in their ways. After all, thirty years from now, young people of today will be the senior citizens of the future, with their own set of ideas and technologies.
But the development should be focused on making operating systems appeal to the widest cross-section of users. This also means designing products that scale well with time. If your desktop is peppered with online integration and social icons, the moment those networks go out of spotlight, your very model loses its own validity.
The current trends and speed can still be maintained. However, alongside every rapid and modern change, there ought to be a solid baseline. Like the Ubuntu LTS. That's a great step in the right direction. Then, Firefox ESR. Another decent one. Those who want fast and furious get it. But you do not forsake the rest. And in developed countries, people are getting older all the time. In fact, they are the majority already and will become an even bigger one as the time passes. Think about it, even for the sake of money, if nothing else.
The sad portrait of the old man is in public domain.
Cheers.