I'm not sure why people are so upset that divorce is widely accepted. It's absolutely necessary for relationships that end up being abusive. Even in relationships that aren't abusive, though, sometimes people grow apart. There's no way to predict that, and relationships that feel as though they will last forever can change, since people change. People should try to marry someone that they do feel as though they could spend their life with, but it's really impossible to predict what will happen in the distant future.
Define "grow apart". Does it just mean losing the intense attraction one feels when one is in a young relationship? If so, that can absolutely be predicted, and shouldn't necessarily be fought against: "comfortable" can sometimes be better than "exciting".