Not mentioned in the article, but one of the major contributors to its failure is that the Lisa was a very restricted environment that made it difficult to develop for:
Contrast this to the IBM PC where people could easily get started programming in BASIC (included in ROM!) or Asm (MS-DOS DEBUG), for which many magazines of the time had listings. Of course not every user did, but certainly a lot of them started and eventually helped greatly grow the amount of software available.
The PC had a learning curve but the user was in full control, whereas the Lisa didn't have much of one but had many impediments that prevented users from becoming developers. This attitude persists in Apple today.
https://en.wikipedia.org/wiki/Apple_Lisa#Third-party_softwar...
Contrast this to the IBM PC where people could easily get started programming in BASIC (included in ROM!) or Asm (MS-DOS DEBUG), for which many magazines of the time had listings. Of course not every user did, but certainly a lot of them started and eventually helped greatly grow the amount of software available.
The PC had a learning curve but the user was in full control, whereas the Lisa didn't have much of one but had many impediments that prevented users from becoming developers. This attitude persists in Apple today.