Sasae and even hiza guruma are great against people that don't know to float over it instead of resist the movement. I think that's why it hits on so many BJJ guys.
I think the main problem with Osoto is that the counterthrow for Osoto is simply more Osoto. At the beginning levels you can get away with less technique, but once you start progressing, Osoto can be a one way ticket to getting your ass countered hard. Beginning players usually think Osoto is about the leg, but with good players the name of the game is winning the hands battle.