Maybe you only consider as "software business" the kind of "software businesses" of VC fame today, like Facebook, Google, and the tons of web based ones, where huge investments are needed for the scaling and infrastructure?

I think the parent has in the mind the more traditional (but still widely present outside the VC echo chamber) model of a company writing some software package and selling it.

(Of course some people don't believe making $5 or $10 or $100 millions a year, as successful such companies do, qualifies as a success, but that's another story).