I'd be fine with that. In that scenario we're talking about private financing, as well as it being built on the fringe of an area. Arenas are terrible dead spots during times when not in use, so building one against the Bay or a hillside would be much better than building one downtown with current active uses on all sides, IMO. In addition, it would be right down the street from the Caltrain 4th & King station and other transit/large crowd infrastructure that exists for the ballpark.