I disagree very strongly with this based on my experience so far.
Being in the business of low volume software is fantastic if your customers are other businesses.
The advantages of low-volume/complex B2B software biz are incredible to me. Contract terms are measured in half-decades. Your users can actually be trained and held accountable in many cases. You don't have to plan for nightmare public cloud scenarios. Your software will usually be running in some firewalled bunker with a guarantee of <10k concurrent users. When operating under these constraints, there are lots of fun ways to manipulate the engineering to your advantage (i.e. SQLite vs nightmare distributed abominations).
Granted, low volume B2B software is just as worthless as any other kind if it doesn't deliver profitable value proposition to the customer. We currently sell software licenses measured in the 6/7 figure cost range (and get away with it because of the complexity of the business and value proposition). This means our little startup can hand-craft each customer relationship and carefully manage the sales funnel for optimal outcomes all around.