I'll play Devils advocate.
Lets say Ford can have a hole machined at a precise location on each transmission. Have a heavy duty grommet formed that seals the needed guide tube into the case. Have that metal tube cut, formed and painted to accommodate the dipstick along with atleast one mounting flange. For savings sake I'll propose an existing bolt or bracket at the top of the engine bay can be repurposed to secure this tube in place. Dipstick itself is likely $tainle$$ $teel, needs some markings engraved at the smart end and overall has got to be some 30+ inches in length and wide enough to read. Have you priced anything stainless lately? Handle you'll need is some kind of molded, heat resistant, brightly colored plastic unit which is then silk screened or otherwise marked as TRANS. Oh, and an o-ring or two at the insertion end of the tube and/or handle base to keep it firmly in place and to keep debris out.
Ford is pretty tough on its suppliers, but lets say including as-needed and on-time delivery to the various US, Canada, Mexico and other worldwide assembly lines, Ford can get ALL this made for $2 a pop all-in. Speaking of assembly line, if this part arrives late or is defective, production comes to a screeching halt. At which point Ford owns you as per vendor contact.
Since the 2007 model year they've made well over 500,000 Expeditions for the US and CAN markets alone. Actually, thru October its 546,247 units per reliable source. At $2 per dipstick, thats $1,047,294 in cost avoidance, plus whatever per vehicle install cost UAW bosses would wedge in.
I won't even begin to do the math on the number of 09+ F150's are out there, the number 06-10 Explorers/Mountaineers/07+Sport Tracs that were made, 07+ Navigators, 2011+ Mustangs, 2015+ Transit vans, or the other non-US models like Territory and over-seas Ranger that have sealed 6R transmissions. Millions upon millions saved. Ford isn't the only mfg doing this.
As a stock owner I want Ford (and others) to find and implement ways to control and reduce costs, increase margins. Sealed transmissions do not need a dipstick. Making one would be a waste of millions as shown above. Since Jiffy Lube actively recruits terminated WalMart Tire & Lube Express employees, I'm glad there isn't an easy way for anyone to contaminate my Ford transmission with brake fluid or who knows what else. I also consider it a positive that a leaking transmission leaves a trail thats easily seen by anyone who parks on any surface that isn't painted bright red. Environmentalists, like them or not, are probably rejoicing fluid isn't needlessly being exchanged so frequently.
Another thinking point: There are millions of Ford vehicles on the road with sealed transmissions without a dipstick yet there are zero aftermarket suppliers (that I could find anyway) who are capitalizing on this "stupid design". Dozens of coolers, magnetic devices, gauges, etc, but no dipsticks.
You should stay away from BMWs. Mine doesn't even have a dipstick for the engine oil. Have to sniff the i-Drive screen.