Perhaps you need to reassess the damage output of these classes then, because in the eyes of most players Commandos are sub-par. Whenever I see them on my scoundrel/vanguard/marauder I know its a free kill and can shut them down without taking more than 20% damage. I would also never willingly bring them along in my premade.
Perhaps you don't know the proper way to play one. If your commando/bh is standing out in open field, yeah, he's going to get rolled by a melee. Same with Sorc's/Sages. Any ranged will get rocked by a melee in open ground. Now give them ramps and platforms... becomes a different story. Most of the time as a Marauder if I'm getting attacked my a range who has the high ground on me I have to run away cuz if I don't it's probably a free kill for them with them only taking a charge for damage before I'm knocked back off and waiting several seconds running around like a target ducky.
It seems to me like you're being narrow-minded to make the situation sound way worse than it actually is.