You know the old adage, "form follows function." You can have a knife designed for a specialized purpose, such as a skinner, superb for skinning and useful for other uses. You can also design a general purpose knife that does pretty much everything acceptably well. There is no end of variation in design. Some of it is just tradition or aesthetics, or ethnic. Some forms, such as the skinner are so well developed that the form is pretty much fixed. You cant improve on the form of the skinners used over a hundred years ago by the professional buffalo hunters, etc. All else is aesthetics. Like they say, "A chicken ain't nuttin but a bird!" and plenty of room for all happily.