客 puts 各 (to arrive, in its old sense) under a roof 宀: one who arrives at your house — a guest. The roof welcomes; the character remembers.
客 rules Chinese hospitality: 客人 (guest), 请客 (to treat someone — with 请), 客气 ('guest air' — polite). 别客气 ('don't be polite') is what hosts say while heaping your bowl. 客家人, the Hakka, are literally 'guest families' — a people named for centuries of migration. And online, 黑客 (black guest) is a hacker: even intruders get the guest character.
Someone arriving 各 under your roof 宀 — a GUEST.
黑客 'black guest' = hacker; 博客 'broad guest' = blog. Chinese absorbs tech loanwords by making them guests.