First of all, Wen Tianxiang is very well-known. It made this poem famous. Secondly, there are many honest poems throughout the ages, but there are relatively few that encourage people to die for patriotism. In addition to Wen Tianxiang's sentence, which basically means that people are destined to sacrifice their lives for righteousness and fail to succeed, they will become benevolent, so the frequency of this poem is relatively high.
By the way, if you are asking this question for homework, then the standard answer should be: This poem expresses the author's sincere emotions, determination to die to make his ambition clear, rich in literary talent, and has historical significance. . It is in line with the crisis situation in our country during the Anti-Japanese War, so it is cited by many patriots.