If they "added some other stupid multiplayer mode" I'm gonna guess two things
#1 they aren't short changing you in terms of quantity, you're still getting the same bangs.
#2 By the sounds of things, you don't actually know what the(se) new mode(s) have to offer, so instead of dismissing them outright, maybe you should look into them first, keep an open mind.
Lastly, I'm not a fan of stealth games but surely, the #1 appeal should be the single player with MP as an after thought? If you were complaining about them taking out single player or something key from it then I would understand but right now...I'm not getting it.