"It's placing the blame on the person you choose to betray that 'offends' me."
Let's dicount the ridiculously loaded way you've chosen to word your posts for a second.
So you think it would be better if people stayed in unhappy situations instead of looking for something better? If the other partner simply isn't willing or able to budge, and it leaves someone in a position of genuine unhappiness, they should just sit on it?