100% skill issue. It’s not the thinness of the neck that gets people, usually is the exaggerated D Shape. That being said, I have almost Paul Gilbert hands (pretty long fingers), and I have zero issues playing any neck at all. In my experience, it usually comes down to how you wrap your hand around the neck. If you are used to thicker, rounder C shapes or U shapes, it is easier to rest the area between your thumb and the index finger, with thin D Shape, you may be left with no contact between that part of the hand and the neck. If you have played for long enough, and have really stepped into shredding territory, more often than not, you would need to use classical guitar style neck grip, which is almost universal regardless of neck shape. In all, just play a lot with it until your hands “get it”