What's right, if drivers are doing it, is to zipper at the point of the merge.
But that's a big "if" -- too many drivers are like your friend, and work themselves up into a blood-boiling rage at the thought of someone "cutting" by engaging in proper zipper merging. Tell your friend the problem is he's thinking of the merge as a competition with a "winner" (person who ends up in front) and "loser" (person who ends up behind), instead of looking for the option that maximizes efficiency for everyone.
But that's a big "if" -- too many drivers are like your friend, and work themselves up into a blood-boiling rage at the thought of someone "cutting" by engaging in proper zipper merging. Tell your friend the problem is he's thinking of the merge as a competition with a "winner" (person who ends up in front) and "loser" (person who ends up behind), instead of looking for the option that maximizes efficiency for everyone.