I saw someone say that if you have a longing to go home or homesickness you’re not really kin, because you’re just using it for escapism? Is that true?

Those people are  talking out their ass, anon. Homesickness/longing to go home is a historic and integral part of the kin experience. Not every single kin experiences it, for various reasons, but most do. In fact, it is commonly the first sign anyone has that they are kin.