It's an inescapable reality: companies grow and grow bloated and complacent. It happened to IBM and Microsoft, it happened to Google and it's happening now for Facebook. Once corporate mentality sets in the company's soul is gone.
My theory is that it involves excessively mediated reality. When Google was two guys, most of the people they talked to were not Google people. Now, my guess is that 95% of their conversations are with people they pay. Those people are more likely to tell them good things than bad things. And those people also think Google is pretty swell, because these who don't leave Google. And at Larry and Sergey's level, they probably aren't within three layers of external reality.
There's a diagnostic term: Acquired Situational Narcissism[1]. Basically, when a celebrity spends all their time around people who act like the celebrity is the most important person in the world, then they too start to believe it. I think there's a corporate version of that.
Imagine it: You created Google. You can buy anything. Everybody you spend time around defers to you. Of course you'd think you could do a better job of designing a social network than Facebook; half of humanity thinks that. The problem is that people will now let you do that.
Once you've done it, your very mediated reality makes it hard to know you've screwed up. Because everybody you talk to needs you to like them. Most of those people have gotten promoted a number of times, meaning they are very good at being liked by their bosses. And who doesn't like good news, especially about a pet project?
I'm not sure it's inescapable, but it certainly is the very common outcome.
I saw Craig Newmark of Craig's List speak once after the late 90s bubble burst. He said people kept asking him why he didn't take up the many opportunities to make money he could have -- just one small ad on each page could have made hundreds of millions of dollars with hardly any change to the user experience. He calmly pointed out how many of them went bankrupt and had to change their ways. He seemed more than content with a site that delivered what its users wanted.
I'm sure they've made blunders along the way, but as far as I can tell they've remained true to their original ways. Wikipedia says they have a staff of 28.
Google has also hired a huge number of Microsoft people, that's going to have an effect on company culture. As well as consultant types from places like Mackenzie, Accenture, etc.
That's the problem with growing fast, hiring like crazy, acquiring like crazy, is that you don't have enough time to assimilate people into company culture properly.