Or stop whining about the Marine's health (that wear BODY ARMOR) and use the crapton of explosives and mines to lure them into traps.
They move in squads so... they do all the work for me after that. heheh... poor bastards.
Go back, read what I said, think about how it relates to what you said. The problem is not my problem, since I'm not having any trouble; body armor has nothing to do with it, since body armor doesn't work the way you seem to think it does, and the problem isn't about hit points or health anyway; and explosives fall under the same category as shotgun ambushes, i.e. tactics that are easy and fun to use but shouldn't be the only viable approach.
While I personally like the balance the way it is, and will probably actually amp up marine damage a little with some modding, this is a design issue which doesn't particularly care about what I think. I worry that they accidentally cut out about two thirds of the combat space in Marine encounters, and in the process compressed their tactical freedom compared to the original, removing a lot of options. Evening out the initial spike on the DPS curve would probably help fix it.
Interestingly this is precisely the opposite problem that HL2 has, where the mid-range space is completely open because Combine soldiers and their SMGs can't hit anything. In HL2 it encouraged a lot of mobility and physics play but also incentivized shotgun rushing, which was pretty dull. Black Mesa's compressed spaces come in somewhere near high-difficulty Mass Effect 3 or Call of Duty, where you're anchored to cover and pop out briefly to use high alpha weapons. I imagine that wasn't exactly what they were going for.
e: The other place this causes trouble is during all the famous marine vs. alien fights where the marines are always winning now. Boo!