At some points it's a US vs UK difference, on some points it's a US vs EU difference. Because it's actually quite complex. Because several other things should be taken into account when looking at this. It's not merely a difference between wanting to date or not, it's a culture difference.
One of the first things is that people in the UK tend to be a bit more moderated compared to americans. Saying to keep in touch in the US often means you can expect a phonecall within a week. In the UK however this could mean there will be later contact, how much later not being specified. But it can also be a polite way to part without any future contact intended.
Another difference is the way of getting yourself romantically involved with someone else. In the USA it's often going impulsive, often doing things without thinking or following christian extremist guidelines (remember, the general way how americans are christian, is regarded as an extremist way in europe) and being stuck to a relationship earlier and longer. As a result lots of people in the US get forced to marry earlier (birthcontrol is less common, marrying early is socially more acceptable, etc). In Europe, especially western Europe like the UK, it's less common to marry early. Many marrying, or being pregnant in the early 20's or earlier are seen as abnormal. As such, boys and girls tend to 'explore their options' a bit more than in the US. Combined with longer and better education it often leads to less time for a relationship and more chance to meet someone while studying or later at work. So dating can last shorter, because breaking up is socially more acceptable
Also, some summer love might be attractive during the holidays, reality of daily life kicks in quite easily. So what might have looked nice across the pond, gets different when you're home and far away.
More things can be involved when looking at the differences in dating culture between the US and western EU, but unfortunately there's a 2500 character restriction. But saying the UK lacks a dating culture is an urban myth. People just get less often stuck to it. Free birthcontrol, easier social norms that make relationships more flexible and a dozen other things mean great dates can be left behind way easier and then sometimes ending up with someone you knew for ages and know you can depend on, might end up to be the best option to depend on for the remainder of your life.