Different in a "bad" way is completely subjective. You did say they force you to play "lame" which I think is absurd lol. I don't think playing defensive against IC's is good with most characters at all.
In a lot of peoples experience it's the opposite of what I said, and I think they are all wrong/crazy and just assume camping IC's is a good idea because someone mentioned it somewhere once, or they saw M2K do it without actually thinking about the reasoning behind it. Yes, IC's punish game is strong...when they grab you and are synched. When you camp you just leave them a ton of opportunities to grab you by setting up favorable stage position with desynchs and burst movement. They can't abuse their burst movement when you are in their face and generally crumble to pressure. It's also very hard for both of them to shield a lot of stuff because nana is six frames behind, meaning you have to shield that much earlier with popo a lot of the time. IC's like having a lot of room in neutral, and claiming stage position against them through aggression is a tactic that is extremely good against them.
I'm not sure what you're talking about with the combo thing. ZSS has no problem combo'ing IC's, go have some fun in frame advance if you don't believe me. IC's are a very good combo weight for most characters. When I say I love that I have to think when I'm comboing IC's I mean I love that I will hit one, and then combo them while keeping my eye on the other ready to switch to attacking the other climber at any moment, or decide in what way I can best keep them separated while hitting both. I almost never just focus on one. Hitting both of them and them staying together only really happens at low %'s, considering nana and popo often end up having different %'s, and nana won't DI. If you are going for a follow-up after you connected a nair and then you get smacked by the other IC...maybe you should have gone after the other IC instead of running past them?
I mean, I'm not trying to convince you to like playing against IC's or anything...I don't really care. I just think it's amusing how many people try to camp them thinking it's the best thing to do. I can't remember the last person I lost to in tournament who tried that against me, usually I just sigh in relief knowing that my they are going to give me a ton of chances to grab them and free stage control, which is a lot easier on me mentally then it is on them. IC's don't have good defensive options, the players that excel against them the most are the ones who abuse that(or play peach loool).
Also IC's grab combos on ZSS suck
. They only truly have dthrow into ledge hand-offs, dthrow dair never works if DI'd properly against her.
Edit: The first IC player I played was wobbles way back in like 2005/2006. He made me love the character so much from just playing against him. I love playing against them probably more than I love playing them, which is why I wish more people played the character. I love the insane amount of thought that goes into the character on both sides of match-ups.