At my last duty station in the Navy back in 2000, all senior enlisted as well as civilian were issued these cards regardless of need or want.
I explained to my supervisor if I was issued the card it would go unused so why issue it. In the end I was told that it was Command policy and it was basically forced on me.
I put the card away in a safe place and left it unused and turned back in when I retired from the Navy. For others, not many, but some, the temptation to abuse the privilege got the better of them.
That is what I was afraid of - That these cards are thrown around willy-nilly and the same people who are issuing them are the ones who are responsible for ensuring that their use is monitored and controlled!
You are right, in many instances it is an invitation to someone to abuse the card, sort of like an attractive nuisance that gets otherwise upright people to go astray.
And this is just the tip of the iceberg!