That code looks normal to me. I have a ton of BASIC books and magazines. You're talking about a time period before full screen text editors were a thing. It's almost impossible to explain to anyone that didn't have to work with TI-99 BASIC, C64 BASIC, GW-BASIC/BASICA, etc. what it was like. Once you got to QBASIC/QuickBASIC it was done. Life was easy. A few years before that, and you're printing out pages on a dot matrix printer and going line-by-line to debug. You'll notice a distinct lack of white space between lines and that comments start with "REM" and a line number. You didn't even get labels for lines. The code looks like that because those were technology limits on really rudimentary devices. You were editing code inside the BASIC interpreter, often using some command like "LIST <line#>". It was awful.
We take so much for granted today. Dual monitors. Color. More than 80x25 character display. Multiple screens and multitasking. Just getting to Linux in '95 and having F1/F2/F3/etc. switching terminals was a huge deal.