CB is doing an excellent job of skiing in that style, but here are my concerns with that style:
1) It isn't efficient. The more the knee is bent, the more muscle strength is needed for support. At the bottom of the turn, when gravity plus centrifugal force add together, the knee bend is at the max, thus the load on the leg muscles is at the max, until the release. Then, the legs push upward to end the turn (release), and this requires more exertion. Tired legs shorten the ski day and ski vacation for many folks. Contrast this with keeping the outside, main weight bearing leg almost straight during the turn, flexing the inside leg to allow for angulation, and reducing the load on the legs by flexing both legs at the release.
2) The load on the knees is painful for someone with some arthritis in their knees, and shortens their ski day, ski vacation, and ski season. I know that well. I do not know if this loading contributes to osteoarthritis.
3) The side load on the knees used to edge the skis at the lower part of the turn loads the ACL. ACL tears are very often the result if many micro-tears plus a relatively minor impact or twist, not always a huge impact or twist to cause the tear. Sideloading the knees might contribute to ACL damage. Women are especially vulnerable to ACL tears due to knock-kneed alignment unless their alignment has been corrected, plus other factors
4) Skiing mainly on the bases of the skis in the first half of the turn and not engaging the sidecut until the latter half of the turn is OK on smooth groomers but can be really tough on difficult snow--frozen-hard crud, for example. Putting the skis on edge and using the sidecut early in the turn works on all types of snow. People are welcome to have as many skiing styles in their repertoire as they want, but having one basic skiing style that works very well everywhere is an easier way to learn and to excel, in my opinion.