I understand your point of view, hard sparring is a huge concern in the majority of scenarios.
But you gotta understand, those men are at a higher calibre than 90% of boxers.
- They're understanding the right blocks and punch/defence mechanics
- They're conditioned to high impact and have the best of the best equipment to keep them from worse injury
- They've got the correct conditioning required for the contest, they've been training for years and years in this exact form. Their necks, heads, movement etc is prepared for the top level.
Whilst i don't agree with hard sparring for most cases, this is an example where two high level fighters are aware of the consequences and can brace with the understanding of HOW to perform in this sort of contact.
This isn't usually the case, there's nothing worse than seeing young fighters or inexperienced fighters get knocked around without the required tools to be able to take the shots.
It's a dangerous sport at both pro and amateur levels, but to get to the next level you sometimes have to train with other people at your level in this regard.