pretty sure some cars have straight cuts for first the same as reverse so its easy to get in to gear when your stopped as opposed to other gears being helical so their easy to get in to gear when your moving...but i think first would be a hell of a lot noisier if they were straight cuts thought, could be hondas designed it like that as a safety feature like a few guys said already or maybe the sincros in first are different due to it usually only needing to be engaged when your at a stop? either way rev matching is your solution