As a former (PhD) researcher, this is spot on. Here are the factors I've observed:
- fear of getting scooped: there's a general fear that sharing data makes it easier for competing labs to publish on the same topics, leading to the publishing lab "missing out" on publications
- fear of being wrong: sharing the data leads to more scrutiny, leading to a higher chance of a fatal flaw being found
- extra work: publishing data often involves jumping through extra hoops with little to no personal gain
- fear of getting scooped: there's a general fear that sharing data makes it easier for competing labs to publish on the same topics, leading to the publishing lab "missing out" on publications
- fear of being wrong: sharing the data leads to more scrutiny, leading to a higher chance of a fatal flaw being found
- extra work: publishing data often involves jumping through extra hoops with little to no personal gain