Hi Ariana,
A lot of men don’t read through a dating profile before liking a woman back. It is possible that they never saw that you had already answered the question about what brought you to the dating site in your dating profile.
The majority of guys who ask this question are open to either pursuing something long term or something casual. They just want to know what category to put you in so that they can determine how much effort is going to be required.
If you tell them that you are looking for something long term, they will go back to your dating profile to give it a proper look. If they determine that there is compatibility, they start putting in the effort to get to know you better.
If you tell them that you are just looking to have fun, they know they don’t have to bother taking a closer look at your dating profile. They just start chatting you up casually in the hopes of hooking up with you soon.