Jon and Kate Plus 8???

So, I have watched this show many times and I think the children are adorable and what not, but I don't understand why they have now become famous? There divorce was completely public and now the headlines say that Jon is suing Kate for custody. I think it's very interesting to see how things turn out to be different than expected. I bet they didn't think they would become famous or get divorced but they did. Maybe it's just me but I don't think I've seen one show where the couple stays together after they are on a TV show together. I wonder if there are any statistics on it or any information? What do you think?