50 years old is a perilous time for buildings - and with them their site, including trees. Our sense of things doesn't usually think of them as "historic" yet, and they may indeed be run down.
It usually takes at least one fairly dramatic demolition to get people thinking seriously about historic preservation. My old neighborhood in Memphis became a national historic district in 1984, AFTER 200 houses were flattened in 1968 (at 50 years old!) for a disputed freeway project that was subsequently stopped in the US Supreme Court.
It's quite possible to champion preservation AND encourage sensitive development. My old neighborhood in Memphis now features 200 NEW houses, designed to look like they were built in 1920. There were design standards put into place to make this happen, of course. And they included a prohibition on removing existing trees over a certain diameter. Google "Evergreen Historic District Memphis". There's even a wikipedia entry...
Old Seagrove is historic now, and will be more so in the future. It's not too late to protect what's left.
PS, anyone who complains about design standards inhibiting commercial success would be ignoring Seaside, Rosemary, Watercolor, and Alys. Sorry, that boat don't float...