MB was not "bought" by Chrysler, quite the contrary. MB made the drastic mistake of buying Chrysler. But that has little to do with the MB problems.
To begin with the JD Powers "number of problems reported" surveys are controversial to begin with and always have been. The problem is that regardless of the problem within a category, they get a check mark. For example, it matters not if an electrical problem is a fuse blowing or an entire wiring harness burning to a crisp, it is still a checkmark in the electrical problem column.
In spite of their vague problem weighting, they do have some merit for the initial buyer. What doesn't show up is the long term life of the vehicle. This is where MB does very well. 250,000 miles on an MB is about like 100,000 on a Cadillac.
Where MB exposes themselves to bad stats is by putting every gadget known to man on their US models. This causes many extra problems that would not occur with cars that do not have such gadgetry.
I have driven MB's for almost thirty years and with every new model there are plenty of people that say "they aren't built like they used to be." Folks said that when I got my first new 123 car in '77 and look how great they turned out to be.
I expect that a young psychology student could do a great research paper on peoples reaction to new models and their commonly pronounced attitude of "they just aren't made like they used to be" comments.
Have a great day,