I can think of a few explanations:

1. To really pi$$ off any JW they ever knew (the old dog-returning-to-the-vomit thing) and ensure that JWs won't bother them, ever.
2. To experience the rituals involved in Catholicism, that they were never allowed to do as JWs.
3. To show their support of the Catholic Church's current stance regarding pedophile priests: official apologies from the pulpit and the Vatican, acknowledgement of the pain and suffering of the victims and their families and financial restitution for the victims - something you'll NEVER see happen with the JWs.
4. To go back to the family religion (if a Catholic converted to the JWs and then left).
5. Because they can.

The WTS did a stand-up job of slamming the Catholic Church at every opportunity - I think a lot of times this tactic backfires and makes people more curious and willing to investigate a belief system that spawns so much hatred from "the competition".

Having said all that, it's not for me to judge other peoples' choices in belief systems - people have as much right to become Catholics after they leave the JWs as I have to be atheist.

Minimus,

I am not a believer now but have been both a Catholic and a WTS lemming.

I own the full run of the Catholic Encyclopedia, I also own a full run of Insight on the Scriptures.

Let us just put it this way, Catholic Theologians are rather more catholic than is the WTS and they are also far more advanced in their scientific and Biblical knowledge than Ted Jaracz and his lifeless flock of career compromised pseudo-scholars.

Perhaps this has something to do with it.

HS

That's cool Andre, but honestly I just don't get how a JW can awaken his thinking skills enough to get out of a cult and then progress no further.

I've left the cult of god for good.

Mini, let the WT prejudice against the Roman Catholic Church influence you no further. 

The Roman Catholic Church is not as controlling as the WTBTS. I was raised Anglican Catholic or Episcopalian. I have returned to my church for the beauty and the deeply spiritual connection it gives me. The Church is very progressive and does not consider the Bible without flaw or to be untampered with. They hold science to be very important as well as reason and tradition when reading scripture.

And the Roman Church? My therapist is a Sinsinawa Dominican Nun. She is highly educated and is a doctor of psychology. She tells me the Dominicans are very "progressive". And they are. She gives me Buddhist prayers and meditations and she also tells me that if I attend a mass at Marywood, I can take communion there, which is normally something you're not supposed to do. That is: take communion at the Catholic Church when you aren't Catholic.

I have a harder time understanding how JW's can go into very fundamentalist churches that border on cult like religions. But then it may be they need that kind of control in their lives.

Personally...I don't see how anyone who would take an hour to research the history of the Catholic church could think seriously about joining them with the view to being part of the One True Church.

If you wanna join just to get a free sip of wine and a bite of cracker, well, sure knock yourself out.  But if it's about the tradition and the grandeur and the architecture, you don't have to be Catholic to enjoy it.  Anyone can pay their money and tour the Vatican and all the other Holy sites.

Touring the Vatican actually caused a Catholic friend of mine to question the motives of the church.  He saw all the history, the hundreds of years of marble, granite and gold churches.  He saw the millions of dollars in artifacts and art.  He then wondered why the church couldn't have used all that power and money to actually help the poor and needy over the centuries instead of amassing one of the largest money coffers in the world.

As far as a former JW joining any other religion...about the only circumstance that wouldn't puzzle me was if a former JW joined a local, neighborhood church that isn't part of a larger organization or church body.  If there is a God, I'm sure he would visit that kind of church before he went to see the Vatican, the Southern Baptist convention or any 'mega-church' organization.  If Jesus was his son, that's the kind of people he would be drawn to...the simple people who worship for the sake of worship and not for the sake of money, power or fame.

I like what Johnny Cash said about churches...he said he felt closer to any supreme being by being outside in nature and seeing the handiwork of his creator.  There was a spiritualism in being alone with nature to him.  He didn't understand why people felt the need to go inside a closed up, man-made building to get close to God.  Something to think about.

I'm having a real difficult time with deciding any denomination to join. I think Raymond Franz said it best when he illustrates how the apostles didn't create separate branches of Christianity to cause followers to say, "I'm a Luke" or "I'm a Matthew" by going with their teachings. I view this the same as with every Christian church because it still follows "men" and glorifies that particular organized religion and separates Christians as brothers. We mold ourselves into labels again by being a "Catholic", "Baptist", "Methodist", etc ...

I wish things weren't so screwed up.