A western cinch/girth/latigo (? whatever) leather strap is almost always sold with punched holes because not everybody ties them off, and not having the holes would preclude using them with a buckle-type cinch w/o additional work. In fact, in our trail riding club I see riders use the buckle about 2:1 over simply tying, and many have gone to a "Y" rigging instead of a traditional rear cinch.
I will comment that tying the strap allows you to get just the right tension whereas using a buckle you have to pick the closest hole (or punch a new one).
I use a "Y" rigging on my western/endurance saddles, with a Weaver Leather "Smart Cinch" (the "Airflex Roper" model for the past several years; highly recommended), and never tie the leather strap. I do punch a couple of intermediate holes between the ones provided to allow a more precise adjustment.
Steve Jernigan KG0MB
University of Colorado