What is a "hookup"? I think that is a great place to start. The fact is that the term has more than one meaning and so it is important to ask for clarification when someone talks about "hooking up" with someone. The first definition is the one I remember using while in high school, about eight years ago, which is to heavily make out with someone. I think of this like getting to "second base." The other definition is "going all the way" or having sex with someone. I find it highly important to consider both of these definitions when deciding to use the term yourself and also when others around you use it.
College campuses are actually massive breeding grounds for "hookup culture." The reason for this should be really obvious. There are pretty much unsupervised sexually charged 18-23 year olds living amongst one another. A study has shown that a female dominated population on campus leads to a large "hookup culture" while a male dominated population on campus leads to a rather small "hookup culture." The reason for this? When males have the opportunity to "sample" a lot there is less of a push for them to "settle" down thus choosing random "hookups" and one night stands.
Why is the rise of "hookup culture" a concern you ask? Well, the marriage age in the past 15 years has been pushed from about 24 in females to about 29 (these are averages through data). The amount of meaningful relationships, regardless of sexual orientation, is all over the place in major cities due to the feeling of not needing to settle down. Another issue that arises is the involves being able to be in a committed relationship that can lead to marriage or something similar. If you never choose to have a meaningful relationship with someone or someones (think polygamous relationships) how are you going to learn how to act when things get tough, fights and arguments start occurring, and so on? We humans learn best from experience but if you don't have the experience where are you learning? From television which shows things from horribly skewed perspectives? From novels where everyone has a happy ending? The reality is we need relationships to learn from and the "hookup culture" completely allows for "easy ways out."
Am I completely against having a few one night stands? No. I'm very open-minded in the sex department and realize having only one partner, while some people want to do that, is highly unusually. Sex is an intimate act but also a primitive one in which we find a particular release so I'm all for women and men enjoying themselves. My concern comes when 29 year old men and women have never been in a committed relationship due to the constant "hooking up." Inter-personal skills develop best through experience and trial and error. This generation struggles because they are so technology dependent and use to having everything fast and easy.