The all matching kilt suit was really popularized by John Brown, but it's always been a part of the Highland dress tradition -- just never as popular as the tartan kilt.

One of the things that I like about the kilt suit is that you can wear the various elements of it separately to create multiple outfits. For instance, the kilt suit that I have, I often wear just the kilt itself causally with a polo shirt or regular button-up shirt. And I specifically chose that tweed pattern because it would look good with many of my other kilts, so I wear the jacket or jacket & vest with my other kilts frequently.