One reason is complexity: with a computer it is easy to go more and more complex, while with electronics it is not - one is very limited in what you can build without going to pay a lot on parts and equipment and even then you are still limited in what you can do.

And there is the limitation in what you can do with it: with a computer you can do various apps (like a notepad, phonebook), some music (Commodore 64 SID was limited, but still fun), some graphics, games etc. With electronics you can do ... how much?

And the time spent on playing games means less time to play with electronics. Time is limited.