Are modern launcher really that all-weather-capable? I quote from weatherspark:
"At Unst Island, the summers are short, cool, and windy; the winters are long, very cold, wet, and extremely windy; and it is mostly cloudy year round."
I appreciate the cloud cover probably isn't an issue for unmanned launches, but conditions ranging from windy to extremely windy present a bit of a challenge, don't they?
There is also the potential political obstacle that it would place space launches under the control of the Fish Woman whose life goal is to transform Scotchville into a hostile foreign power - why hand her more cudgels to beat us with?
PDR