Some like Charles Poliquin said the smith machine was dangerous because it forced you into an unnatural movement pattern 
For years, I never touched one because of that. Tate made me rethink it. I remember it was said Poliquin lost some respect at Westside because he didn't work in, and train when offered. That was a Louie test, he offered to let you train if you visited, if you skipped out, and only asked questions, it dropped his estimation of you.