I'm pretty sure I performed combos in soul calibur 2. The ones I did mostly consisted of launching the opponent into the air and then juggling him.
I think the problem with the lack of strings in brawl is that whenever you successfully approach someone, you can get 1 or 2 hits in before they knock you away with their fastest attack, and then you have to approach all over again. This becomes troublesome vs characters with large priority or a good projectile game. Wherein melee it was easier to punish someone that spaced poorly and they had to make more of an effort to escape your follow-up attacks.
Bottom line is that there is a LOT more room for mistakes in brawl, this is coming from someone who had never heard of wavedashing until 2006.