Oddly, one way to encourage that is to make the permitting process easier. Tech companies want to all be in the location, because its much more desirable to tech workers, and the belief that the best talent is worth the price means that money is made available for that.

Without the restrictions on development (which are designed to keep the area desirable, and succeed at that, as shown by market prices) desirability would drop -- because you'd have more people, and less money for services per person -- along with prices, and tech companies would be more likely to locate elsewhere.