In the US their Sprinters compare to the competition about the same way an S-class compares to a Camry. In both cases it's generally considered ill-advised to own it into old age.
If the Sprinter took a comparable amount of maintenance to deliver the same service it would not have the reputation it does. It's not like people are jumping to conclusions based on brand either. It was initially branded as a Dodge or Freighter/Sterling. The only operators who like it are high end passenger fleets that depreciate them and then get new ones. Now, in its defense, people do generally hate the FWD Fiat van more...
I've seen some of this. People were bitching about their MBs not lasting long enough: turns out they were skimping on the oil, using regular oil rather than the synthetic oil those engines need. Synthetic oil is a lot more expensive but it lasts much longer. But America likes its oil changes, every ridiculously low number of miles because they believe that is what will make their cars last, rather than to use quality oil to begin with.
MB engines are indestructible if treated properly, they routinely outlast the body of the vehicles, they have oversized oil pumps, use chains rather than timing belts (a common failure point) and in general are designed to last.
There is plenty wrong with MB, their electronics absolutely suck and don't get me started on their software or their over priced parts. But their engines are solid.
I wouldn't call that "entirely different"