ArcC-
Not sure exactly wah you mean, but an old bowyer I knew, used to make a laminated "V" bow, that had the swept back look, I think you're refering too. He claimed that the entire riser flexed with the shot, and so, made the shhot that much faster. Don't know it that's true, or not, but his bows were among the fastest recurves I've ever seen. The one I bought from him, though a little beaten up, still shoots like a charm to this day.
With marketing as it is today, a sexier looking bow, has to help sales, only problem is, what's "sexy" today, may not be tomorrow.
Viper out.