I suspect (based on nothing so take it for what that's worth) that the FogCreek Illuminati feel burned by the Trello experience: there they carefully tended, had high organic growth, spun it out to its own company after three years, and ended up selling for less than half a billion dollars
in 2017. This is bad because 2017 was quite probably the highest valuations for privately held technology companies in this cycle, and they weren't a unicorn, unlike plenty of other companies at the time- Quora raised 85m at a 1.7g valuation in April 2017, to pick a business that FogCreek would know well.
SO, like Trello, took a long time to find a business model (honestly Trello never really did); it seems clear that SO Jobs didn't work, but enterprise sales is the key, just based on what they emphasized in the announcement. Using the SaaS website as a loss leader advertisement for the shrinkwrap software is an interesting model: I see it as somewhat similar to the old 'give away Unix and C free to universities, sell System V to the companies those students work at' model, modernized for the internet age.