A book I highly recommend to entrepreneurs is the 22 immutable laws of branding. He cites a lot of statistics, and explains a lot of phenomenon that I have observed over the years. Perhaps it just fits my biases but it is the best explanation of branding I've ever read.
Anyway, specifically in that book he principally discusses highly specific branded products versus this "master brand" idea. The problem with master branding strategies is that people make up their mind about a product based on the brand, and they don't change that if it's for a new product. A for instance is the tradition Chevy / Ford / Dodge debate. Most people seem to be drawn to one of these brand, and they generally don't switch between them. So even if Chevrolet introduces a brand new car that would solve someone's needs, if they are loyal to Ford, they won't cross that line. Oddly, with a sub-brand like Corvette, it's positioned outside of that battle so people don't feel like they are crossing the picket line.
Other examples include Pepsi / Coke, Mac / Windows / Linux, etc. Food companies have known this for a long time and don't prominently feature their company brand name on their food products. Instead they focus on the brand of the product.
So what is the theory that underpins this belief? Most people associate a brand name with one thing. Quick off the top of your head, where do you buy your home electronics? How about computers? Where do you buy your Garden Supplies? What about your books? Did you know that Amazon sells all of those things? Most people associate Amazon with books, and while they do sell those other things, the bulk of their revenue still comes from books.
The article claims a sub brand approach is more expensive, yet everything I've ever seen shows differently. It's much more expensive to try to build a brand than to market the specific benefits of a given product. Particularly for a startup, the best way to enter into a market is with a highly focused niche in an industry. Focusing on a master brand makes that extremely difficult to do.
Sorry, kind of a long rant, but I really think that article is misguided.