Arm knitting annoyed me at first. It seemed like it was diminishing the importance of knitting & SKILL it takes to actually knit (I feel this way when people machine knit & call themselves a knitter).
I ended up deciding to try to "arm knit" a scarf. It was okay, but it's annoying because if your arms are big (like mine), there's only so small you can make the eyelets.
After giving it a try & judging for myself though experience, I decided it just wasn't for me.