Being a black belt in Judo I like to think my throws are okay, but having had many BJJ matches I'm telling you from experience that a lot of the throws that work well in Judo just don't function the same way in BJJ. People don't stand upright, and there's no ref forcing them to not stall on the feet or penalizing them for defensive grips. In addition, if you stand bolt upright in a good Judo stance, your legs are very vulnerable to shots. And comparing it to freestyle Judo is a little silly, because even under that rule set ippon ends the match. I can throw you and land with you fully on my back and it doesn't matter because the match is over. That is not the case in BJJ. Judo's a great sport and one I spent a lot of time training and competing in, but it isn't BJJ and no matter how much Judo guys want to elide the differences it never will be.