i've competed using a false grip in competition for many years.
I've benched in the mid 500's raw in the gym and have a met best of 515 raw with a thumbless grip.
How is it more risky? I've competed thumbless AND used a reverse grip in competition and put up 485lbs. At no point did i feel unsafe.
If you don't like it that's fine but don't throw out blanket statements like that. There are plenty of people that use it and use it correctly and in a safe manner. I train with a team of competitive powerlifters and all but one of them do all their pressing movements with a false grip.