Because 180 damage is a fucking lot, even for rhino.
With one of the last updates, mercs that use explosives as abilities got a damage buff, along with a range nerf, but, still, i think its too much damage when we talk about: Direct AoE with more control, unlike skyhammer or arty.
Even my phantom, with a full charged refractive armor hit from nader or fragger leaves me with less than 10 hp.
I just think explosives deal excessive damage, even though most mercs dont even have 100 hp. I would like to know your opinion about this.