Compared to previous products Line 6 has made, that also cost a lot less money.
I love my Helix, but still, we shouldn't have to take a step back in a lot of major categories just to upgrade to the latest [very expensive] modeling tech. Microsoft did something similar with the Xbox One, where it's missing a lot of the nuanced features that made the Xbox 360 great, and three years later, they're slowly adding all of those features back. This kind of thinking damages trust. We WANT to be Line 6's cheerleaders, but it's currently a little hard to justify.
The user interface and hardware are AMAZING. Probably the best I've ever seen, but there are times where the list of amps and effects feels extremely lacking, almost barren, compared to the HD500. People don't want to have a Helix PLUS their pedal board. They want to be all-in on the Helix, and they get frustrated when they can't.