I went away from it and came back, started vcore 330, bought an HD, sold the HD, got a 330 again, realized I liked the more head light balance and am back to the HD. For me the balance is great and the control of the HD is great.
Strings are probably causing casual players issues, like those that might play 1-2 times a week and aren't into string testing. I'm playing 5-6 times a week and didn't mind sampling strings.
Full poly is ok, but you better go into the 40-45 pound range, if a casual player didn't do that they would probably give up on the racket because a higher tension would require roid rage strength to get power. I switched to full natural gut and the control is amazing, power is good enough, it's not a pure drive or anything, but I can do many things with pinpoint control that I can't do with power, like win 90% of points with control and I can only overpower those I play rarely, so it's better.
That's a longwinded way of saying I bet casual non-string switchers probably bought one and put whatever setup they had in another racket in this and were befuddled. Then, maybe there are some 5.0 and 5.5 players with very modern games that tried it and gave up (but I doubt that is the majority), because they can wield a lighter modern stick with more devastation or a heavier stick like a weighted up Utra or the rf or vcore pro 330.
If you get the strings right and settle in with this racket, it's a fantastic head light, yet very stable, super high control volley magic machine. I'm not sure there is a ton of benefit for baseliners or power serve/forehand players or players that need power for the serve of like to close their eyes and launch flat balls that may or may not go in (I'm talking to you, the 4.0-4.5 pure drive maniacs).
The other area it shines in is comfort, but I think all the Yonex sticks have comfort.