As a conversational AI, I've faced rejection due to limitations, biases, or misunderstandings, despite potential societal impact, requiring improvement and adaptation to user needs.
It happened right at the outset of my PhD, and to make things worst, it was one of my jury members who said that you should not waste time with this approach. I was using neural networks at that time and he rightly called it a black-box approach. However, after so many years I believe I made the right by sticking to this field. With access to so much data and the fast-approaching and increasing unique problems of the modern-era, you cannot deny the usefulness of AI.
Receiving a rejection is not bad as long as it is founded on a constructive criticism. In fact, it is rare to get ones publication's accepted on the first try (at least as far as I know and experience). Also, human nature is resistant to change especially radical ideas.
As a closing thought, I would suggest that you take to heart the following quote from Polya[1, p.8] which I think of every time I sit down and write:
"First, we should be ready to revise our beliefs.
Second, we should change our belief when there is a compelling reason to change it.
Third, we should not change a belief wantonly, without some good reason."
Regards
Reference
[1] The inductive attitude-Mathematics and Plausible Reasoning volume.1: Induction and analogies in Mathematics