The reason it's going to the carb is Positive Crankcase Ventilation (PCV). Besides the emissions, PCV is very helpful in minimizing oil leaks as it creates a slight negative pressure in the crankcase. If you are going to vent straight to atmosphere, I would recommend a larger opening and pipe from the crankcase. There is at least one unused port near where the vent/drain from the oil tank comes into the cam box.
Google "benefits of positive crankcase ventilation" or something similar and you'll find plenty of reading.
It also occurs to me, there is a related issue here. IF you are running with your oil tank vent/drain in the lower position (which was typical from the factory) it will not fully drain oil mist after use due to having a low spot in the tubing run. AND if you make a few short trips that don't fully boil off accumulated moisture in the crankcase especially in these cooler days of autumn, you can end up with a foamy sludge blocking that vent line until thing warm up. SO with the vent line plugged, on startup, the engine cannot vent excess pressure to the tank and it has to go somewhere, so the intake vent tube seems like a good place, blurping oil into the intake.
Search on this forum (or Google it, as the search here isn't great-Google results for M3W searches typically bring up this forum!) for posts on M3W breather or crankcase breather and you'll find posts on the simple drain line modification to help these issues.
