This article focusses on new college grads. The questions remain, are college grads the right choice for startups and are startups the right choice for college grads. The answer will probably depend on the type of startup, the grad and time available for mentoring and training the new grad. Though I suspect the majority of silicon valley startups concentrate on hiring experienced people in the early stage before they have the resources and time to invest in new grads.
Personally I would prefer to work a couple of years for a more established company to become expert in certain technologies and learn how stuff happens at "real" companies.
There are tons of different startups. I feel like you're talking about extremely early stage startups, or startups started by college students themselves.
A startup founded by seasoned founders that's been alive a year or so is actually quite a good learning environment for a recent college grad. They will have good coding process in place, good communication, etc.
Personally I would prefer to work a couple of years for a more established company to become expert in certain technologies and learn how stuff happens at "real" companies.