It's not about lifetime because often they been shot right next to the other mech with zero distance.
Instead i would prefer if they had smaller damage as well as smaller cooldown.
I find it not funny when i try to use them against units. I wait sooooo long to shoot them against units simply because people complain it is too strong against meches.
So what about -30% overall damage as well as -30% cooldown? The main issue with missiles is how deadly they are.