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.