It isn't a good test for that either.

Having a successful business requires a lot of factors that don't really have anything to do with software engineering. Things like luck, connections, access to funding, good marketing, etc. And while have good engineers on the payroll undoubtedly helps, the good engineers aren't necessarily the ones getting a big fallout from the acquisition and may not stick around for long after the acquisition, especially if they get put on a project they don't care about.

OK, let's go to the source then and ask Claude:

What's the difference between a software developer and a software engineer?

The honest answer is that in most day-to-day contexts, the distinction is more about company culture and title preference than actual job duties. A "software developer" at one company might do more rigorous engineering work than a "software engineer" at another.