The Altair really raises an interesting question – and I personally have to admit that I have no clear answer for what a home computer actually is for.
The early kit computers like the Altair, which we may call enthusiast’s machines, were clearly more about having a grip on the technology, in gathering some personal knowledge and experience, much like more conventional science kits, chemistry kits and so on. I guess, if there was any goal in this, it was about “doing stuff with this thing”, the particular task probably being more of a pretense. The media/technology was the message.
When home computers became more of a thing, or more mature, marketing tried to suggest particular use cases which would turn this into some kind of home appliance. However, apart from replacing a typewriter (with dot matrix printers a rather questionable endeavor), much of this didn’t make much sense after all. Say, I want to listen to the Beatles’ White Album. Would I really want to get my VIC-20 out of the cupboard, hook it up to the TV set, connect the Datasette, find my tape with the audio cassette database, load and run it in order to know that the cassette ought to be in the second place in the third row, where it probably isn’t? Again, the audio cassette database, everyone’s favorite example for “what can I do with a home computer” is more about building it, in being in contact with and passing time with this technology. (The other goto-application, which also offered some visual appeal, the biorhythm, eventually faced some questionable reputation, ultimately dismissing its prospects of becoming a tech-affin replacement for the horoscope.)
The often praised educational aspect is probably similar to this: Even, if it boiled down to games, it was at the same time about a general familiarization (the educational effect not that dissimilar from what you may expect from a chemestry kit). The message was still, using a computer. (I guess, this was also true for a number of games, which were solely bought to have another thing to pass time with on the machine, regardless of any particular expectations.)
Modern private computers are probably for the most media display stations, telecommunication terminals for exchanging messages (there’s a bit of irony in this one, since most technical communication advances were about remote communications becoming more realtime, while it’s now more about decoupling by intermediate storage and retrieval – except, when it isn’t, being more about disrupting your otherwise essentially non-modal media or work environment in realtime), and, of course, about games. And there’s a certain mood about this, suggesting that the media is still the message…
(Enter the IoT, where you sign into your pocket terminal in order to sign into an app in order to connect to a server in order to adjust a light bulb. This, too, is probably more about the media than about the application. Like with the maker movement and playing with microcontrollers, where making lights blink becomes a viable application again. Much like on the Altair.)