why do a lot of boxers keep their guard down?

Speed. Alot of boxers create openings by fighting with their guard done, forcing the other guy to commit so they can land punches.



Some like Mayweather fight with their guard down because they cant be hit anyway.

 

To lull the opponent into lunging or exchanges.

 

It's not exciting to actually be defensive aka Wladimir Klitschko. People prefer complete ******s.

 

some do it to see better and may use head movement and/or feet movement for defense anyways.
Then some may do it to make their opponent think there is an opening and when your hands are low, you can counter at more angles.

I feel personally when my hands are down, I can slip punches better also

 

Its harder to see them coming when they're fired from the hip. Carl Froch also said he fires from the hip because punching in a straight line doesn't feel natural.

 

Speed, angles, style and some people drop their hands because it's tiring having them up all the time

 

make a four round sparring and try to keep them up in the fourth round

 

Practical when one needs to pick his nuts.