Blow-by gasses contain contaminates. Unless the crankcase is purged by fresh air with a properly functioning PCV system, your oil will more quickly become contaminated.
I did the PCV reroute...and while not a perfect system, it eliminates the oil ingestion problem during hard right turns.
Everyone that claims that they have deleted their PCV system and have no issues probably haven't had their oil analyzed. Oil contamination may not be obvious by looking at the dipstick