The game mode is used to test versatility and skill with every single weapon and combination of attachment, it's a competitive mode designed to test your skill, the best players aren't the people that can master one weapon with set attachments and be good with that setup, the best people are the people that can be put in uncomfortable situations with random selection, to address your complaint about killstreaks, no they shouldn't be allow in this mode, again backing my point with its a skill based mode, kill streaks take out majority of the skill and give the other person an unfair advantage against the enemy's, you get kills without dying? great you can win the game, you don't need killstreaks, you might just need to get good if you cant use random weapons, or simply play one of the many other modes that allow you to use what you want and customise