The advantage of blind rivets is that they provide their own "nut", so to speak, when they squinch up at the other end; and this without needing access to that end. As you know, an awning rail can be subjected to quite a bit of force; for that reason, attachment by means of a simple no-nut wood screw is usually not recommended.
" Not every mind that wanders is lost. " With apologies to J.R.R. Tolkien