That is a very interesting observation considering the cost to fix or straighten out a DEF system problem.
In addition to the stupidity of offering DEF, but not near the diesel fuel pump, my on-going aggravation is the new marketing strategy of gas stations with mini-marts. The industry trend is to slow the pump speed down to lengthen the time to refill. The theory is while you are waiting and waiting you will walk in and buy a soda or bag of chips for some extra $$$.
I was at my regular diesel station that underwent the change. But I didn't realize it yet. There was a line of vehicles waiting to refuel and I thought WTF. Seemed I waited forever. When I finally worked my way up to the pump, I found the pumps had been slowed to 2 gals/minute. I needed about 60 gals, which would have taken 30 minutes to pump. Screw that.
So I bought 10 gals and went to a different station. I've never gone back. And I didn't buy any chips or soda ....