>Secondly, there is a lot of religious imagery in the speech. I could certainly imagine people objecting to having the speech presented in a secular school.

At my (public) high school (10ish years ago), we had "character education", and one of the "character words" we had (there was a new one each month) was "respect for the Creator", which is:

A) Actually four words.

B) Insanely, crazy religious.

I assure you that the religious angle is not why this is not presented in full in schools.