Another way to look at it is that the activity being done in the big company is usually going to be much larger scale and affect many more people than the activity being done at the startup- those small groups of startup people pushing through ideas by force of personality/lack of resistance can easily be engaging in just as much bikeshedding, it's just that in a smaller org there's fewer people and lower stakes. Smaller orgs are by definition going to be more agile than larger orgs, but that doesn't grant them more wisdom, just the ability to execute bad decisions more quickly. The only way to avoid bad organizations is to stay out of them, regardless of size IME.