That may have been a reference to that fact that many computers of the early 80’s had a basic rom that would be booted into if no operating system was found.
Not in a technical sense, but in a historical/cultural sense, sure. At the time PC/MS-DOS was propagating out in the public, many of us were also working with machines where the "OS" was a BASIC prompt. And the model and syntax of command interaction wasn't so dissimilar.
But yeah, it's a bit of a hand waving generalization.
Some early PCs would boot to a basic environment if it couldn’t boot to any other OS. Not sure if that extended to machines that could run Win3.1, but IBM 8088 PC-XTs (and similar, but that’s what I had) definitely did that, though normally one would boot them to DOS.
A history lesson for some of us (including me, tbh, because I was only vaguely aware of any of this and wasn't born yet at the time):
> The emergence of microcomputers in the mid-1970s led to the development of multiple BASIC dialects, including Microsoft BASIC in 1975. Due to the tiny main memory available on these machines, often 4 KB, a variety of Tiny BASIC dialects were also created. BASIC was available for almost any system of the era, and became the de facto programming language for home computer systems that emerged in the late 1970s. These PCs almost always had a BASIC interpreter installed by default, often in the machine's firmware or sometimes on a ROM cartridge.
> BASIC was one of the few languages that was both high-level enough to be usable by those without training and small enough to fit into the microcomputers of the day, making it the de facto standard programming language on early microcomputers.
> The first microcomputer version of BASIC was co-written by Bill Gates, Paul Allen and Monte Davidoff for their newly formed company, Micro-Soft.[21] This was released by MITS in punch tape format for the Altair 8800 shortly after the machine itself,[22] immediately cementing BASIC as the primary language of early microcomputers. Members of the Homebrew Computer Club began circulating copies of the program, causing Gates to write his Open Letter to Hobbyists, complaining about this early example of software piracy.
> Partially in response to Gates's letter, and partially to make an even smaller BASIC that would run usefully on 4 KB machines,[e] Bob Albrecht urged Dennis Allison to write their own variation of the language. How to design and implement a stripped-down version of an interpreter for the BASIC language was covered in articles by Allison in the first three quarterly issues of the People's Computer Company newsletter published in 1975 and implementations with source code published in Dr. Dobb's Journal of Tiny BASIC Calisthenics & Orthodontia: Running Light Without Overbyte. This led to a wide variety of Tiny BASICs with added features or other improvements, with versions from Tom Pittman and Li-Chen Wang becoming particularly well known.[23]
> Micro-Soft, by this time Microsoft, ported their interpreter for the MOS 6502, which quickly become one of the most popular microprocessors of the 8-bit era. When new microcomputers began to appear, notably the "1977 trinity" of the TRS-80, Commodore PET and Apple II, they either included a version of the MS code, or quickly introduced new models with it. Ohio Scientific's personal computers also joined ...
> When IBM was designing the IBM PC, they followed the paradigm of existing home computers in having a built-in BASIC interpreter. They sourced this from Microsoft – IBM Cassette BASIC – but Microsoft also produced several other versions of BASIC for MS-DOS/PC DOS including IBM Disk BASIC (BASIC D), IBM BASICA (BASIC A), GW-BASIC (a BASICA-compatible version that did not need IBM's ROM)[28] and QBasic, all typically bundled with the machine. In addition they produced the Microsoft BASIC Compiler aimed at professional programmers. Turbo Pascal-publisher Borland published Turbo Basic 1.0 in 1985 (successor versions are still being marketed under the name PowerBASIC).