I hope for season 2 as well, because I hate open endings and I think it's a lazy writing. With no exception. No, it doesn't "make you think". It's just a hipster-writer kind of thing to do. I want to know author's story beginning to the end, no matter how hard it is for them to finish it. If I wanted to read a fan-fiction I wrote, I would write one, I don't need to be given that choice to "pick". Even if I come up with 100s of scenarios, and choose most probable one, end of day it still didn't happen because writer stopped in the middle, that's the only fact.
I don't care if 2nd season would be much less popular with people, I am not 14 years old, don't need some kind of "special endings". I am very content with day to day regular dramas where characters go through life events you can learn from something, even if it is metaphorically, which most people seem to hate these kind of dramas and find boring.
Potentially I could see it with a timeskip, where they are all together and trying to pay back the society, as well as make money, by hunting down other gangs doing same or similar work but treating girls poorly. And I hope it was Mr Lee who showed up in the end, with the pretext that he faked his death before. Hopefully Minhee is alive too. And hope Kitae is in on it, as bad as he was as a bully, and did not redeem himself, especially how he treated other classmates, he still had some saving hope. He cared about Minhee in the end, and went out to revenge her, even if he revealed her name in the end, as he was still battling the good and the bad in him.
With netflix, if ratings are right, it is more common to see season 2, especially because authors are more incentivised to do so, considering it is Netflix, international brand, and they are starting their careers.