I've gotten medicine and food missions since 1.4.
As for why I do it, it is because the trading and the haul and everything is why I do it in the first place. Except for a very few times where I had to build back up from a loss or something I have stayed away mainly from the rare trade. I did a couple Sothis runs but that was it.. Am doing the Hutton trucker's run all over heck right now.. otherwise I've only carried mugs once before.
Until my back made it impossible, I drove long haul for about a year after I was retired from the Air Force.. bathtubs, meats, paper, beer, band-aids.. just normal stuff.. wasn't any high value metals. Everything was the stuff people use and need. So I gravitate towards that.. yes I still look to make a profit so I try not to carry loads that cost, but machines, medicines, foods, clothing, legal drugs are what I usually carry.
Plus while the galleon of gold and treasure is always popular, that is not what pirates usually found, or took. Pirates usually went for normal things.
And you even spoke of why.