Lately, I've noticed a meme from investors about discerning founders who can start companies and those that can grow beyond 250+ employees. The generally consensus is that there are very few entrepreneurs (Zuck for example being one of them) who possess the capability to scale. I'm not talking about scaling servers, I'm talking about scaling organizations as quickly as their revenues grow. Looking at it through the lens of an external person, this may seem trivial at first, but having been in the professional world for 8+ years now, there are some key challenges all companies hit when they hit certain growth (for example, hitting 50 and 250 employee milestones). Working for a big company can (notice I didn't say will) prepare you for that.
So, pretty much any business? There are so few companies out there, especially venture backed ones, that the employee headcount hasn't scaled with the growth. We just hear of the Instagram/WhatsApp acquisitions with low head count so often here in the echo chamber that we assume it's norm. To take that further, how many companies are at FB/SalesForce/WorkDay/Twitter-level that don't have over 500 employees (much less 1,000s)? I can only think of very few - 37signals, Valve, etc?
My larger point - VCs in SV want to fund billion dollar businesses and founders who can create billion dollar businesses. These billion dollar businesses need large amounts of headcount and a CEO who can take them there.