Why is Floyd soo afraid to be hit?

I know he has a great defense, but it looks like Floyd is desperately trying
to not be hit even with a little snap. If you compare for example to Whitaker,
that guy's body movement was perfectly timed with the incoming shot, in
mayor situations Floyd is able successfully apply that timing as well .... but
if you see Floyd being cornered or on the ropes then you can see the difference.

Whitaker was always trying to get out and rearrange the position, Floyd is covering
desperately and trying to lean out all the incoming shots even if they looks like a tiny little giggles.

The question is then why is Floyd never trying to do any exchanges,
but in first reflexes always is afraid of receiving even a single .... JC type snap?

 

Some people do ... but its not like they are receiving everything (Gatti exception),
they try to miss some punches while at different time they receive shot just
to find good opening for his own shot.

In Floyd's case it seems he is trying to avoid EVERYTHING which is thrown
or slapped at him, and unload his own shot only when the other guy stops
throwing his punches or he is safe enough to not receive anything ...

 

But Floyd is a very good counter puncher himself, his own shots even if not superb powerful are timed well and he stopped or floored good opponents. Why then rule out the possibility to engage into some exchange with the additional openings in the way, in this case he could finish his opponent faster and overall receive less collective damage in a shorter fight.

But that would involve some risk factor ... so is that the case Floyd goal is to minimalize all the risks in the first place then rely on his own skills to get the win?