There are
very few pure-play software companies.
Microsoft is simply alone in its class as a large, pure-play, shrinkwrap software company. Adobe might come close.
IBM, Oracle, SAS, PWC, Deloitte, McKinsey, PeopleSoft, and many other firms bundled software with at the very least consulting services. IBM, along with Sun, HP, Digital, and other vendors sold (or leased) both hardware and software, along with consulting services.
Smaller software companies have existed, but have been notoriously fickle.
Novell existed as a network services company, doing well for a while, but ultimately faltering.
EDS is probably the closest thing to a precursor to today's SaaS / XaaS companies, and was ultimately in the services business and bought by HP IIRC.
I've been looking at this question for nearly two decades, and the most substantive conclusion I've come to was that Microsoft was a unicorn, a lone star, a singleton. And yet everyone's tried to emulated them. Or at least did until Google came along and cracked a different market.