There was a tradition of using Basic from the days of printer terminals. A language with s-expressions doesn't work well with printer terminals, and a language

There was a tradition of using Basic from the days of printer terminals. A language with s-expressions doesn't work well with printer terminals, and a language with line numbers does. Lisp would also probably have overloaded the hardware of early microcomputers. And then of course there is the fact that Basic seemed accessible, and Lisp seemed frighteningly advanced. Even Lisp hackers seem to have thought so in the 1970s.