I think one of the reasons why C became popular in industry and Lisp didn't, is because Lisp is harder to translate into efficient machine code. C was closer to how the hardware works. In the earlier days, specialized hardware was built to run Lisp code: Lisp Machines. When computers were sufficiently fast enough, the specialized hardware was no longer necessary.
The software industry could have been vastly different, if Lisp took off instead of C, which I think had more to do with business, culture, & politics than the technology itself.
Until the 1980s, there were various different hardware architectures, each with its own operating system. Their manufacturers sold mainframes/mini-computers which came with the operating system installed. The operating systems weren't portable, and were included in the price of the hardware.
Unix was originally developed for the PDP-11, and written in C, which though influenced by the PDP-11 architecture was at the same time low level and machine independent.
BSD Unix was available for the DEC VAX, and could be run instead of DEC's VMS. Back then, this was most people's first experience of Unix. Franz Lisp was included with BSD Unix.
Around this time, the market for proprietary mainframes was collapsing, so there wasn't much demand for their operating systems (or for people with experience with them). New manufacturers, e.g. Sun and Apollo, entered the market with workstations running either Unix or Unix-like systems. Vaxes were still around, by now often running Unix instead of VMS. Anyone manufacturing new hardware had the choice of developing a proprietary operating system, which was a lot of effort and would die with the machine, or porting Unix to it.
The Lisp Machine market collapsed for various reasons which are reasonably well-known. Lisp lives on, but was always a niche language, and there are various explanations for its lack of popularity. It was never really an alternative to C, which is a lot lower level.
Which only happened thanks to the AT&T tapes that were taken to Berkely, and the work of Bob Fabry.
If it wasn't for that, BSD Unix might never have happened.
> Anyone manufacturing new hardware had the choice of developing a proprietary operating system, which was a lot of effort and would die with the machine, or porting Unix to it.
Because UNIX's source code was available under a "cheap" license.
If it was an AT&T product like those mainframe OSes, that would never been a path they would take.
Portability was important for Unix's success. The other operating systems were free (as in beer) but wouldn't run except on the expensive machines they came on. ITS could have been free, and wasn't proprietary, and was (at the time) a better development environment than Unix, but it was limited to PDP-10s.
MS-DOS was proprietary but was more popular than Unix, because it ran on even cheaper hardware.
Nothing prevented the other companies to port their OSes, many of each were implemented in variants of Algol and PL/I, they just didn't saw a business value in doing so, and thus lost to the availability of an almost freely available OS, that universities which didn't want to pay for mainframe OSes, adopted to their existing computer labs, instead of getting more licenses.
Students at those universities then picked UNIX for their startups, for the newly workstation market, like Sun did.
There were only two operating systems written in high level languages before Unix: MCP and MULTICS. Burroughs mainframes had a 48 bit word, and Honeywell mainframes had a 36 bit word. Burroughs and Honeywell were interested in selling those machines, not in spending considerable effort porting their systems to competitors' hardware with smaller word sizes. There was no business value in doing this.
Unix, which was very much influenced by MULTICS, initially ran on 16 bit machines. It's a lot easier to scale up (to run on Vax) than scale down, which is why Stallman based his GNU project around Unix rather than attempt to port ITS.
I don't think people under 45 remember what the software was like before. Everything including AT&T Unix had a high price point and many "versions" of Unix that caused incompatibilities. LISP systems were extremely expensive and rare. The number is around 7,000 units sold up till 1988. In 1987 Unix became a "Thing" and in 1989 as a teenager I built a fiber optic network with a friend of mine and used System V running Word Perfect and Lotus 1-2-3. It ran into the 21st Century :)
> "In a move intended to unify the market in 1987, AT&T announced a pact with Sun Microsystems, the leading proponent of the Berkeley derived strain of UNIX. However, the rest of the industry viewed the development with considerable concern. Believing that their own markets were under threat they clubbed together to develop their own "new" open systems operating system. Their new organization was called the Open Software Foundation (OSF). In response to this, the AT&T/Sun faction formed UNIX International.
The ensuing "UNIX wars" divided the system vendors between these two camps clustered around the two dominant UNIX system technologies: AT&T's System V and the OSF system called OSF/1. In the meantime, X/Open Company held the center ground. It continued the process of standardizing the APIs necessary for an open operating system specification." - http://www.unix.org/what_is_unix/history_timeline.html
The software industry could have been vastly different, if Lisp took off instead of C, which I think had more to do with business, culture, & politics than the technology itself.