"once a company reaches a critical mass of size..."

"the giant couldn't really do what they [Moi ici: They = Davids] do because, once a company reaches a critical mass of size, they have different problems. Brands stop focusing on being good at what made them great and start being great at making much more of what they make. They're no longer a master brewer; they're a supply chain company.
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This insight is important. I put this question to each entrepreneur I spoke to because I was genuinely interested in understanding how they took this plunge. Couldn't the giant in their industry just squash them if they wanted to? Well, yes, but .. . they can't. Anheuser-Busch technically could retool their breweries to do what Samuel Adams beer [Moi ici: Um fabricante artesanal] does, but they won't. It isn't worth it to them. It would take up too much of their attention and time for too little a gain.
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The Procter & Gambles of the world don't want their brand managers focusing this intently on developing that much expertise in a finite space. Their job is to do well and get promoted in eighteen months to another bigger job." 

Trecho retirado de "Killing Giants" de Stephen Denny