MsPhD brings up an interesting point: what is the duty of people in the field to ensure the success of the next generation? Modern science has reached an interesting place where the talented and engaged scientist is able to continue to contribute for an extremely long period of time. In many cases, the ability to have people with this refined level of judgment around is really important.
But there is also a tension with the newer generation. In biomedicine we have seen less of this tension lately because there was recently a big expansion of funding. But now that we are getting back to a more stable funding paradigm, it is worth asking what is the balance between mentoring new people and continuing work.
It'd be more obvious if the barriers to entry were lower -- mentoring a new investigator is hard work; can or should we find creative ways to make it more rewarding?