Perhaps the bigger lesson here is to not do personality tests. With that said, obviously gauging team fit is super important - but you don't need (and should avoid) a test for that.
On a related note, it seems another lesson to be learned from here is to be cautious when searching a technical job at a non-technical company. We don't know whether this is the case in OP, but nevertheless the whole "BigCorp" caution you give is likely more applicable when you look at financial companies or otherwise "companies that don't focus on making software/etc."
But I have no idea why growing startups would model their HR after them. If they want to model their HR after a "Big Corp" then they might as well model it after a technical Big Corp. Let's not compare apples to oranges.