If you are getting a PhD, chances are you or your professor applied for and received funding for a specific research project - and that's what you research. Obviously an advisor will guide you towards doing work they can advise on, as is their role...
At the end of the project, results are expected and reported. Broad significant outcomes are unlikely without lots of clean data, so the trend is towards narrow-but-significant outcomes.
Reporting is biased against publishing insignificant outcomes... that's a valid criticism. Peer-reviewed publication is a lot of work to announce "we found nothing". However, that is not a valid critique of peer review - even null results are thoroughly vetted.
Despite flaws, peer reviewed science is still clearly superior to commercial research - which suppressed climate change, smoking cancer, and the effects of lead air pollution for decades.
At the end of the project, results are expected and reported. Broad significant outcomes are unlikely without lots of clean data, so the trend is towards narrow-but-significant outcomes.
Reporting is biased against publishing insignificant outcomes... that's a valid criticism. Peer-reviewed publication is a lot of work to announce "we found nothing". However, that is not a valid critique of peer review - even null results are thoroughly vetted.
Despite flaws, peer reviewed science is still clearly superior to commercial research - which suppressed climate change, smoking cancer, and the effects of lead air pollution for decades.