I often have a lot of respect for people (esp girls) who break up with their other half. It is all too easy to just plod along in a relationship because it's the obvious and comfortable way to go. It avoids drama, heartbreak and hard feelings. But those who have said 'right, I don't think this will work' are amazing because really, they are the sensible ones. Who knows what they are looking for in life, know what they want, and has clear enough head (and lots of courage) to step out and do something about their lives. They have clearly thought things through, weighed up the pros and cons, and made a sensible decision. These are the ones who will eventually end up in a lasting relationship/marriage in years to come.
Many relationships in uni work because it's convenient and can easily last several years. You're in halls together or at most a coupla streets away. However the end of uni is the real acid test. It's called a make or break time - I'm talking about couples who have been together a while. A year down the line you can easily tell that it almost certainly swings one of 2 ways.
They either get engaged (or married) within a few months. Or they break up within half a year.
Where there is strain in the relationship - be it geographical or simply a lifestyle change - it will come apparent very quickly whether you're prepared for this person to be your future wife/husband.
Over the past year (which for me would be a year after uni) I have seen so many uni friends break up having had 3, 4 or even 5-year relationships. It's saddening cos they've undoubtedly put a lot into it and you always thought they'd end up together. But really if you come to think about it, most people at the end of uni are merely in their early 20s. A lot of girls aren't really mature enough to get married or even knowing what they want, let alone guys. And working life is just... so different. Gone are the days of 'mucking around' and enjoying a carefree social life. You battle work, stress and neverending responsibility on a daily basis, whatever profession you're in. Your routines change, as does your aspirations and priorities. Inevitably, the way you see the world and your life alters, in some way or another.
There's no real right or wrong. Just a fact of life.