"Morbid" refers to a concern about death or illness, and typically refers to the person's own death. On the other hand, "pathological" refers to the quality of producing harm to others. I'll grant you these are approximations, but they're essentially correct. When we speak of persons with socially dangerous personalities we say "psychoPATHS or socioPATHS" while those who are continually worrying about their own death, we say they have"morbid personalities".
Similarly, we speak of dangerous bacteria or viruses as pathogens, not morbidogens.
Accordingly, if Thom wants to characterize the uber-rich as dangerous, the term "pathologically rich" is a more apt descriptor than "morbidly rich."
Granted, a rose by any other name...