Jeremy McGeary won an award for this piece. This is just an excerpt from the full article available on Practical Sailor but is a clear concise listing of cause and effect on sailboat design, especially a lot of what is "new" in boat design. There have been performance improvements but performance can also be overblown by marketers. Much of what is passed off as "fast" these days is simply the shape that evolved in order to cram in an apartment sized dwelling space.

"Let’s face it, but for a few differences in sailplans and keel shapes, modern cruising sailboats are quite generic below the sheerline. They are all beamy; they carry their beam aft; they have long waterlines; they have dinghy-like underbodies; and they have spade rudders. The forces that have created this shape have at least as much to do with how many people can sleep and shower in them comfortably as with how the boats will sail."