Taking up a collection is a good idea, gets everyone on their toes about watching each other's backs, and puts the responsibility on the entire community. If each participant threw in a buck or two, that's a new MacBook Pro.
Once your laptop is stolen it's more of an issue of all your stuff being stolen as well (that is on the laptop) as opposed to just a piece of hardware. How are you supposed to do your thing if your laptop which is setup just for you has been stolen and you are at a hackathon?
(As a side note when I travel I travel with a cloned hard drive (encrypted) that can be used to boot another laptop.) Hard drive is always on carry on luggage as well. Cloning tool that I use is "super duper" (that's the name)).
That said, the laptop cost is a big expense for many people (especially students), so it's helpful. Also it's a nice gesture. (“Look, the community cares about you.”)