Well I've just about had or used most of the 1980's - 1990's micro computers as they were known then, and to be honest I agree with the report. I too spent most of my time typing in lines of code, and punching in hundreds and thousands of hex characters in to a small 30 line basic program in order to program the machine in machine code.
The thing is we were (are) fond of it because it was our first machine, and we burned away hundreds of hours of our lives away on it, and enjoyed doing it!!!. When the spectrum came out it really did blow the ZX81 away. The ZX80 and the ZX81 were very similar, but the Spectrum was light years ahead, as was the C64 from the Spectrum as was the Amiga A1000 from the C64 (I know I am missing the Vic20 C16 etc) All the Amigas were just about the same (I had em all) A500 A500+ A1500 A2000 A3000 (yes a bit faster) the A1200 started to make some head way with the new graphic chip, and hard drive, but by then windows 3.0 was out and it was game over for Commodore.
Don't forget there were the MSX machines around the time of the C64 - Tandy's effort - Uk101 compukit (all were better than the ZX81) but some did come after it
but were ALL to expensive for the average man in the high St when you compare the price of the ZX81.
But back the the original statement, I don't think I did anything useful on any of the 8bit micro's if I'm honest, I wrote the odd crappy program, but mainly typed in other peoples. The C64 came with basic and you could program in machine code, a friend of mine used it all the time, but like all the other 8 bit machine - it was games. Only when I had the Amiga did I realise the true potential of what the micro (now not so micro) could do and set up a printing business designing business cards on it eventually upgrading to a PC.
So there we have two chaps who were there at the time - doing our bit for the computers of the 80's, both with different memories of the time - lol
Neither of us is wrong I think...