Now more useful than ever.
With the release of 2.0, a whole host of new gameplay elements has come into play, one of which is the shotty. It now shoots much faster, as if it were in the hands of one trained to use a shotty. It also does more damage, and costs less. This makes it much more viable to be handed out as a standard marine armament.
A 3-man team of marines, one armed with a shotty can plow through most anything, even fades with little trouble if they're skilled. The age of the 'HMG is end-all-be-all weapon for marines' is long gone. Squads of marines with mixed weaponry is the newer and most effective way to use your resources.
A 6-man team.....if you've got the res......all with HA. 2 have shotties, 2 HMG and 2 GL, and they all have welders.....mmmm......as long as they stay a little spread out to avoid the evil onos stompage thing.....