Define successful and define scientist - Lysenko was quite "successful" in the Soviet Union for obtaining funding and influence because he flattered the ideology of the management. His work however was complete bunk and didn't even hit upon real epigenetic interactions.

They may get rewarded for it in dysfunctional systems but it isn't furthering science.

That is the question, yes, and I think that was what jhbadger meant by “successful” - that one is so in science (from this perspective) similarly to any other field; when people buy into your work, give you funding, your reputation increases, etc.

To the level that this is true (the "reproducibility crisis" has been blown out of hand because the general public confuses reproducibility with generalizability), this is because of the exact opposite of what you claimed earlier -- it isn't "groupthink" but the exact opposite -- the individuality of scientists not thinking as a group and wanting to demonstrate their own unique takes rather than just redoing what others have done.

the cynical in me says that many scientists choose to forgo research that would disprove some semi-established research in the fears that their work might get heavily scrutinized as well. I think you 're talking about "great scientists" which are extreme outliers. Scientists often enjoy that mythical appreciation, but the truth is a lot more pedestrian - there are 7.8 million researchers , 0.1% of the world's population.