Because they aren't worth it for any boss fight at all. Rather have a sniper and do way more damage.
English
-
Perhaps a boss fight in the future could have benefits to being close
-
That would be sweet. Maybe like an arena type with plenty of room but also plenty of cover with a larger slow moving boss. All bosses also have a OP close range attack that will kill you 1 hit or relatively close to 1 hit. So as of right now it isn't a great strategy to get close to them.
-
How about a pattern of attacks from the boss? Some require you to get close, others far.
-
Sepix prime
-
I do more damage with a couple clips of PnT or IB. Also if your close to him for more than 5 seconds your dead.