What is the likelihood of being issued crappy gear in the Active Army Infantry (the vests, magazines, rifles, helmets/straps, MOLLE gear)?

See Murphy's law

Depends on your definition of crappy.
There is Civ crappy
Army crappy
Marine Corps crappy
or Air Force Crappy (which means it was issued and not in the original plastic bag)

If you get “crappy” gear refuse to sign for it until it is replaced