Elisabeth Kolbert^ strikingly showed why we must carry-on-doing-what-we-are-doing in philosophy.
Critically, philosophy is an actual method-and-discipline and we can learn from it just as say others do learn
from social science or just science.
And for "objective philosophy" it can reveal some unknown or buried truths which become more-and-more
important for even pure Philosophy's study.
And after more than 12 years on this site I believe that I have the experience to say that..
Nevertheless the "proof of the pudding is in its eating" & so again I will say that there is NO
reason for anyone who believes in the truth (behind or from) knowledge STUDY to get too
downhearted or unenthusiastic about studying philosophy.
That is, objective philosophy*
* its search-for-truth, critical truth so-to-speak
^ see, read & try to understand how Kolbert et al show the current dangers of AN OBJECTIVELY UNPLANNED FUTURE,
A future that is unfolding where (environmental) philosophy needs to be at the very front-of-knowledge.
A PLANNED (& critical) STUDY we may say.
The Sixth Extinction ; an unnatural history by E. Kolbert.