I mean, I don't regard US soldiers in Vietnam as having fought for an abominable cause the way Nazis or Confederates did, and the Memorial Wall is definitely meant as a reminder of the shame of sending men to die for nothing more than political posturing. The US picked the shittier of two shitty sides in a war we had no business being in, not unlike the Central Powers of WW1. But I also don't get worked up over it, because ultimately:

A. It's not like it's disrespect towards soldiers who fought for genuinely positive causes, however flawed, like the soldiers of the Union or US soldiers in WW2

and

B. I understand that the undisciplined conduct of US forces in Vietnam and the indiscriminate and criminal decisions of the US government during the war raises a great deal of justified antipathy.