From what I read in the article, the 159 was too little tire for the MH's. It is up to the MH's manufacture to be sure the tires can carry the max axle load. That doesn't excuse Goodyear from not knowing the application the tire was to be used in.
Kind of like the Firestone and Explorer deal. Ford wanted less air pressure to make a truck ride like a car. Firestone should have pulled their tire. Firestone didn't make the <STRIKE>Exploder</STRIKE>Explorer roll over, vehicle design, overloading and driver error did. But that is another discussion.
To this day, I still see new MH's with small tires that need to be near max inflation.
An example is a 2008 Monaco Dip. Front GAW is 13,000 pounds. The Goodyear 670 275/70R22.5 H load range has a max load of 13,880 lbs at 125PSI. The tire has a the ability to carry only 6.7% more than the GAW. So if you are maxing out the front axle at 13K, 120 PSI will give you a cushion of 460lbs, and 115 PSI has only 20 lbs of extra capacity.
I don't know what the front of a Diplomat could weigh, but the tire and axle are very closely matched. Not much room for error.
A tire is considered to be have possible structural damage if run at 80%, (in the Diplomats case 92 lbs), of normal operating pressure.
JMHO, Stepping off my box again