It is all about people. When company grows, there is a choice needed to be made between holding the hiring standard and maximizing short term revenue, for publi

It is all about people. When company grows, there is a choice needed to be made between holding the hiring standard and maximizing short term revenue, for public traded companies there is little chance of choosing the former. And it is always exponentially harder to get rid of bad hire than hiring bad people. For google, at least before 2006, I did not know personally anybody does write bad code got in there. Until I start to see someone will always copy and paste code from internet and try to make some code barely works made to Google by just consistently practicing coding questions, the trend is quite obvious that none of stuff coming out there has a distinct quality differences compared to other technology companies.