The article is based on what dealers charge for service.
MB and BMW just charge more for routine service items than most others, and it doesn't actually mean they require more service items to be performed. There is no good reason why it should cost that much, other than they know that MB owners have more money than Hyundai owners. I guess that is why there is an independent MB shop right across the street of a MB dealer near where I live.
In any case, BMW provides free routine maintenance for the first 3-4 years, which should take the sting off the maintenance costs. Also, even if one cannot change the oil themselves, I assume changing the air filter, cabin filter, etc can be done by most owners.
MB has the Mercedes-Benz Premier Prepaid Maintenance that allows owners to "lock in" the costs of the required services for up to 4 years or 40,000 miles. It costs about $1500, but not sure what that actually covers.
As I mentioned above, there is no reason why one must take a car to the dealer for routine maintenance. However, I would not take any car to a Jiffy-Lube.