Former U.S. veterans were shocked at how listless and unprofessional Trump's parade was, and the theory is that American soldiers were annoyed at having to perform for Trump's birthday, and didn't give enough of a shit to perform to a high professional standard.
View: https://m.youtube.com/watch?v=RmvUx6vcnjM
www.buzzfeed.com
We Asked An Expert Why Soldiers Were Marching So Badly In Trump's Military Parade, And Her Reasoning Makes Sense
"Every soldier learns how to march during basic training, and it's not hard."
I desperately don't want to do the prep. 
