Erm... That's not true.
There are two sorts of developers who don't like hackathons. There are the go-to-work-and-write-code-and-then-do-other-stuff-in-the-evening sort of developers who are the overwhelming majority of the sort of devs you meet in business. For most developers writing code is nothing more than a job. Those people see a hackathon as work, and they don't like it. That's great for those people; they get code done and go home.
The second sort of developer who doesn't love a hackathon (and I'm in this group) is the sort of person who enjoys the process of writing a great piece software rather than just concentrating on the fun bits of solving a problem and getting something on a screen. I see a hackathon as literally all the worst things about software development compressed in to a single event - practically no planning, very little testing, zero documentation, no sleep, bad food, not seeing your non-dev friends, and not stepping away from the keyboard for any substantial time. I've worked on real world actual paid projects like that and it's awful. I definitely don't want to do it for fun when someone isn't even paying me for it.
I love seeing the result of other people's hackathons, and I'm glad that people who attend them enjoy them, but seriously, if you think all developers love a hackathon you really need to expand the group of developers you hang out with.