“How come?” is a colloquial/slang expression that means, roughly, “Why?” “How does it come to be that…?” is a longer way that is unlikely to be heard. How does one set rules for slang? “Why doesn’t Tyler remind you of Josh?” “How come Tyler doesn’t remind you of Josh?” Using “How come” allows you to state the result, “Tyler doesn’t remind you of Josh.” “How is it that Tyle