It seems to me that there is a preoccupation within academia to getting published in venues which are highest-ranked in terms of some sort of metrics rather than venues most suited to one’s subject area albeit not high-ranked.
It occurred to me that any reason for this must be self-serving. I don’t feel comfortable with this idea. As opposed to self-interest as the actual motive, are there any better reasons for submitting to top-tier journals/conferences rather than low-tier ones?
Assuming that your publication is indeed sufficiently exceptional to be published in the respective journal:
As already mentioned in a comment, high-ranked journals have a higher visibility outside your specific subfield. This applies to scientists of related disciplines who may translate your work to their field, but also to news coverage and similar that communicates the achievements of science to the general public. Indeed many high-ranking journals have a criterion that your work is of general interest beyond your specific subfield.
While this attention benefits you, it also allows the scientific community and the general public to benefit from your insights more than a publication in a lower-ranking journal does. Moreover the additional attention may benefit your field or subfield by highlighting its usefulness to funding organisations and students who might venture into this field. Finally, it slightly benefits science in general by communicating it usefulness to the general public.
If your results are not entirely based on luck, they may indicate that you are indeed a comparably capable scientist and funding you is more likely to advance mankind than funding somebody else. Thus your egoistic interests are to some extent also altruistic. Or with other words: The academic system’s evaluation mechanisms are based on high-ranking publications and getting people properly evaluated helps science and academia. By not participating in this system, you are harming it.
Now, there is some criticism on the idea of ranking journals at all in times of the Internet where hardly anybody reads articles by journal anymore, and one may consider it more ethical to fight and boycott this system than participating in it due to the above reasons. But that’s a decision you have to make for yourself and this platform is not fit for discussing it.