"Amen, I say to you, Judge not, lest that you be judged. For the full measure that you mete out shall be meted un to you...Before you point out the speck in another's eye, take the plank out of your own." 
In my experience most Catholics do not divorce out of convenience but rather dire, chaotic and even dangerous circumstances such as alcoholism, addiction and abuse. Staying together  "for the kids" in those types of circumstances is not advised. We might due well to remember that Christ does allow for divorce in cases of sexual immorality. Scratch one of those causes that I listed and see if you don't find such. 
So easy to judge those who have divorced and remarried isn't it? So easy to tell others how to navigate this difficult world. So easy to mark with the scarlet "A". Harder to try and understand that you don't know all. That communion, or not, is between the sinner and God. "Sinner"? Yes, everyone approaching the altar is a sinner, don't kid yourself.