I suspect it is uncommon to be kicked out of RCIA. I've never heard of that happening, but I can imagine it. Most people really want to be there and it should be for them. Now someone with many more questions, or a particular style that does not fit in with the group might need individual attention.
Sorry for your experience. Sounds like they should have found someone to work with you individually and they failed you. Hard to know because I wasn't there, but that is what I might have tried for you.
I've met many former Catholics and many of them fall into a particular pattern. They were not terribly well raised as Catholics, either by the fault of parents or church, they went away to college and fell away from the faith. Then they ran into some evangelicals or fundamentalists. They discovered for the first time what they should have discovered as Catholics years before: a friendship with Jesus. They blame the Catholic Church for this failure, and to a degree maybe they are correct. They are fed a diet of anti-Catholicism and they eat that up along with everything else. What you end up with is someone who never knew much about the Catholic faith, even if they went to Catholic schools, because it never sank in. They think they know more than they know, but most of what they 'know' is anti-Catholic talking points.
You can tell because what they claim to know is usually lame, or blatantly false, and/or just the standard talking points. They are often bitter anti-Catholics themselves. It's obvious they haven't ever had an adult Christian faith as a Catholic.
This sort isn't everybody, of course. Mileage varies. I can be happy for this sort, that they finally did find Jesus. Better late than never. But they can be so confused about what they said they once believed. I facepalm a lot when I encounter this sort of person.
It's the evangelicals and fundamentalists who sometimes have their talking points all ready to go, but those talking points lack depth. Take for example the talking point about 'call no man father'. It's easy to whip out and deploy. But the answer, that takes a chapter of a book to fully answer. And the answer is sound, Biblical, historical, and satisfying. But that same person who launched the 'call no man father' attack will be unfazed by it, replying that the Bible sez ....
It's that sort of person who seems uneducated and truly uneducatable. Not everyone is like this. But there are plenty of them. They stick to their talking points, unwilling to learn a thing, attacking, hoping that by doing so they will save some of us from the Beast.
Catholicism is not an easy to understand religion. It doesn't reduce nicely to a few sentences. Every little thing has a book or three behind it. The Scriptures can be complex, and what was built from those Scriptures can be even more complex. Even the Catechism, designed to be simple, is deeper than it is simple. We have a partially systematic theology, which means that it cannot be treated as totally systematic (annoying those with systematic minds), and also if one does not engage in any systematic thinking it doesn't make sense either. Some other Christian groups can boil it all down to 'Bible sez' or a short list of rules and be done with it. We have long explanations, because we have thought about this stuff for many centuries, and that sounds all wrong when compared to 'Bible sez'.