Having recently moved to Livermore, I am not knowledgeable with the various community groups and business and civic interests in the city, so I look through a different lens at the downtown park/development.
I'm not privy to the economic details of placing residences on the park property, but I am aware of the multiple-residential community planned on the lot bordered by First St., L St. and Railroad Ave., bringing some 200-plus dwelling units to the downtown.
My lens sees a park property that serves the community for the next three generations, as once it's built it will stay that way for a very long time (e.g. Carnegie Park). It needs to be planned with park users in mind, not necessarily dominated with residences – as these needs can be provided in other locations.
If you're going to create a masterpiece, it will take time and patience. A place for people first, economic benefit second. More open space for families, dogs, out-of-town visitors and relatives to enjoy downtown, and spend their money here. More parking, a larger hotel with more amenities that will draw visitors, and something to be proud of.