An easy argument can be made here in regards to all Final Fantasy companions -- all of them have their ups and downs. So, why are we picking on this guy, right? Well, it's bad enough that that damn cat is riding on top of a fat/stuffed Moogle, a somewhat of a mockery of a beloved Final Fantasy character that many fans hold dear, but it also has reduced number of limit breaks.
The choice here is very obvious. Don't want this thing to be in your party? Switch it out! We are certain that there are many other companions that are far better and more powerful than Cait Sith.