Bard. What if Straight Shot "proc" was not rng?

[Shurrikhan]

tbh I just keep wondering why the SS proc is a % instead of proccing on DH's

Probably because at that point gameplay becomes even more dependent upon gear, meaning that if gameplay is intended for something like late-expansion secondary stat levels, it would feel underwhelming until that point, or if built for early-expansion levels, would scale out of hand by the end of it. Fixed chances provide level gameplay across varying secondary stat levels, whereas stat-dependent gameplay can often even turn into unintended quadratic gains.