In HoX 1, Jean explicitly says humans aren't allowed on Krakoa unless invited. She says that they must be accompanied by a mutant at all times and even then its really up to Krakoa itself.
That reminds me the way women are treated in some countries in the Middle-East…
“Strength is the lot of but a few privileged men; but austere perseverance, harsh and continuous, may be employed by the smallest of us and rarely fails of its purpose, for its silent power grows irresistibly greater with time.” Goethe