Their contribution to the culture of startups, awareness of the importance of "nice people", creating the alumni network, fostering a supportive and intensely creative atmosphere within YC during the launch phase, diffusing good ideas and practices. Jessica, as part of the YC leadership (especially with PG's support and encouragement), has been central to that, both figuring it out and getting it all to actually work day-to-day.
Beyond the core YC team, this cultural progress has been possible because of a broad receptivity in the generation of potential founders that have flocked to YC. If Paul & Jessica had been alone in their attitude, they never would have developed momentum. It's been part of a generational shift in attitudes towards business, and I love that.
So thank you both Paul & Jessica for being so open about YC, and for having an attitude of service, and to everyone who has worked together with them! Here's to future generations of idealist entrepreneurs.