i'm sorry but people seem extremely lax with their ratings these days
tbh it's bland, doesn't flow well, and doesn't even look like terrain (maybe it would if it wasn't all white, lol). i honestly don't understand what it's supposed to be. doesn't look like any island i've ever seen.
try adding some variety. it just looks like a big steep.. mass of blocks. maybe have some less steep areas, color it to look like an actual island, add some grass/trees/bushes, something like that. maybe add some structures, a dock would be cool. maybe a radio tower on top. who knows, use your imagination.
honestly 3/10 right now. BUT, fix it up a bit (you don't have to do any of the things i suggested, those are just ideas), and it could easily become an amazing build. it's a good start, but it's just that.