It's alright saying "pick another map, problem solved", but that's not the issue - it shouldn't be too difficult with every block having it's own ID, to ascertain if the spawn is in water and, if it is, to either move it or build land around it.
There really isn't any need to be defensive: We should not be spawning in the bloody sea, there isn't any need to excuse this behaviour.
I know nothing is simple, but creating an algorithm to avoid this spawn behaviour shouldn't be too difficult for Craig.
I mean, look at the amazing game he's created: it's astonishing. I just don't want to spawn in the sea!