I'm the only person I know of that actually likes having the marines in halo around. Almost all of my friends would complain about how we had to babysit them and would normally shoot them as soon as the mission started.
I, however, enjoy their presence and treat them as valued members of my squad. I think this is mostly because of the fact that they have infinite ammo. Whenever I run low on ammo for a weapon that is really powerful I give it to a marine so I don't lose the power of that weapon. I really enjoy giving marines rocket launchers and fuel rod cannons and letting them ride shotgun in my warthog. Makes vehicle sections far easier.
I, however, enjoy their presence and treat them as valued members of my squad. I think this is mostly because of the fact that they have infinite ammo. Whenever I run low on ammo for a weapon that is really powerful I give it to a marine so I don't lose the power of that weapon. I really enjoy giving marines rocket launchers and fuel rod cannons and letting them ride shotgun in my warthog. Makes vehicle sections far easier.