people bought them for games. very few cared about the keyboard. there was the spectrum+ with a better keyboard but was not very popular.
Most, yes. But not everybody.
And of course the Sinclair with the better keyboard didn't sold well. It was more expensive. For not so much more you got a C64 or CPC464 which also not only had the better, but way more games.
It's not all 100% vs. 0%
If I say 'all' or 'most' I mean app. ~70...90% And yes, even if it were 99% you may find that 1% that's otherwise.
But that does not prove anything.
As I said somewhere above: Within the world of free markets there always at least three aspects to be looked at the same time:
technology, society, and business
Everything always is kind of a mix of those.
If something becomes the best technology available, it's luck.
What's best for society may be decided in the long term.
But in short and midterm business always wins.
Who could you have sold a computer to in those days?
Kids.
What do kids want most?
Play.
So yes, of course, most of the times it was all about games.
Just like today kids want a Windows machine with colorful blinking watercooled CPU, and a bleeding edge graphics adapter - because that's where the most thrilling games run on.
And, please, don't come with the 0.1% of kids, that start on a TTY only FreeBSD learning Python, just to prove not all kids like games only. And yes, I know, also adults find fancy colorful flashy hardware thrilling - beancounting brings us nowhere.
But those were also the days when computers entered homes, and became accessable for anybody. And some also used their chance to get one for not to play with them, or at least not only. Because most here were either kids in those days, or not even born yet, while those who did not (only) played with them are not posting in the majority here.
But they do exist.
The popularity of a computer was also decisive for the user.
In those days people could only meet in person, maybe give a phone call ("landline" -
wired - you all know that yourself!) So, if "hackers" wanted to share their experiences (and black copies of games, of course), especially want to learn programming together, you better had a machine everybody else had. For that Sinclairs were also a drawback - at least in the 1980s in Germany they were more the exotic kind of machine. Most had a C64, followed by the CPC464 on second place, and later the Amiga, or Atari, this topic is actually about.
But besides we are talking pre-ST/Amiga era, so offtopic, my post was about why the Z80 resp. its clones were so popular in eastern europe those days - not why computers sold best.
And especially not, which computer were best.
And again while it's ~80% vs ~20% it is of no use to argue if it were 79% vs 21% or 82% vs 18% ...
Bottom line:
This is all fourty years ago ancient history. It's over. This is just another nostalgia thread again. It's about telling war stories from the trenches, and not about who knows what about computers, FreeBSD, and programming today, which is all what really counts.