There you have it. I still differ in opinion, though, RadarMan. I had a customer who was an admittedly sloppy hunter. He said his leather sheaths were trashed from the blood, guts, hair, etc that he would shove into the sheath. He also preferred hunting in downpours, insisting the best whitetail came out during storms.
So, for that guy a sheath that was two pieces that could be completely separated for a real good cleaning (who wants to get salmonellosis, right?) made sense. For most knives a permanent means of closing the sheath as RadarMan suggests is adequate, but for blood and guts you can't beat the preventative health care aspect of a take-apart sheath.
Not only that, but I've looked high and low for eyelets and moreso for the tools to press them and the tools are exorbitantly expensive. For under 20 cents a piece I can use high quality screws which will last forever. Most sheaths only need two or three, also, so it's a low profile design to boot. Glue and rivets require extra tools and time to do the same thing. Not too long ago I receieved a customer's knife in the morning, made the sheath, and got it into the mail that night, which wouldn't have been possible with glue. To each his own, though!
My Custom Kydex Sheath page:
Palmer College of Chiropractic
On Two Wheels