Shlock, are you Sephardi or Ashkenazi?
And for some reason, most Sephardim also do kapparos even against the psak of the mechaber. There is a Yabia Omer Teshuva explaining why.
Rav Ovadia who always paskens as the mechaber also did kapparos. Arizal also did.
I'm Ashkenazi and you're right, it does seem like kapparos has survived many rabbinic challenges over the centuries. For hundreds of years, rabbis have been trying to ban kaparos. The Rashba, the Ramban, the Bais Yosef and more recently, the Aruch Hashulchan all wanted to ban kaparos. Some did, and no one listened, others did not because they knew no one would listen.
Classically, the primary halachic objections to kaparos are the issue of "darkei Emori" (pagan ritual) and the likelihood of flawed shechita due to the high volume of chickens being shechted in a short amount of time.
Kaparos lives on. In fact kaparos with chickens has only increased in popularity in my lifetime.
Fascinating minhag...