To make a computer as we know it today, everything had to be invented. There was no such thing as an operating system. There was no such thing as a mouse. Semiconductors opened a whole new realm of possibilities.
At the time, even in Silicon Valley, there was no environment where one could raise money and start a company, and any available money was carefully restricted in terms of what you were allowed to invest in.
Meanwhile, Stanford and Berkley, these universities became sources of people interested and capable in technology, and the universities were wonderfully funded. So it was a perfect environment for technology startups, from that point of view.
They were built in an interesting way. They were on a lake and everything came in a barge, so a barge would come along with cole, with steel, and the barges kept coming along with raw materials, went into a big factory and a car came out.
They would only built black cars, and they did wonderfully well, but they never got the message that other cars (blue, white...etc), were just as desirable, maybe more desirable than their black cars.
At the very beginning, instead of having a partner choose a startup they want to join, Sequoia lets the startup choose a partner they'd like to work with. This creates for a better dynamic that reduces complexity and let's the team to work faster.
Furthermore, Sequoia partners are not allowed to display bad manners. Everyone pitching them is ought to be treated with respect, recognizing that founders are there to do a hard job.
Peter Thiel and Sean Parker teamed up to make sure Sequoia was not part of Facebook's early round. However, future sales of Instagram and WhatsApp to Facebook had given Sequoia a sufficient steak in the company.