Orange County is now built up. Back in 1988 the El Toro people complained about "population encroachment." Back in 1988 the commander of the base objected to the building of a medical center on Sand Canyon Rd (if you are familiar with the area) as it being under the flight path.
The hypocrisy of the "movers and shakers" of Orange County was that developers: the Irvine Company, the Mission Viejo Company, Argyros' Arnel got permission to build around the base over the years while at the same time the rich Republicans of Newport Beach were dreaming of using El Toro for commercial aviation. Had nothing been built around it you could have buily there an airport now.
When the county government came with the plan for an airport it called for no flights over homes - going northward and eastwood against basic laws of aviation where takeoff is with a head wind, meaning, toward the ocean.
Plus, it called for an airport the size of San Francisco International. You are not going to get all these passengers when LAX is only 35 miles away. And I sympathize with the impact on its neighborhood, but the leaders of LA: county and city, always talk about what a great economic engine LAX is, providing jobs for people in the inner cities.
Not every county has to have its own airport, not when there are five others within 50 driving miles.
Yes, a fast train would be ideal. Even extending the foothill toll road all the way to Ontario would do the trick. Ontario is operating at half capacity and the leaders of the Inland Empire have been begging for more passengers and cargo, saying that they were ready and willing and capable.
The area around the former Norton and George bases has become a major cargo hub with many warehouses. For air cargo you need a lot of warehouses and the land around El Toro is too expensive for warehouses.
As for the great park: had the navy just transferred the base, they it was doing all over the country, the dream of the park could have materialized. But when it announced that it was auctioning the land - well, you either find a sugar daddy who would pay a million an acre, or you have to rely on developers to buy the land and to madk a deal - develop some and leave the rest open space. And, yes, golf course are considered open space for this purpose, thus 80% are expected to remain open space. The nicest part would be a corridor to connect the open space preserve along Laguna Beach with the Santa Ana Mountains.
http://greatpark.ci.irvine.ca.us/