That's not even remotely equivalent to what the original statement was.This confuses me. So the Halo games are shit enough (to you) to not bother playing them on your own, but ok enough for you (and others in this thread apparently) to share that shitness with your friends in the same room?
By changing the activity it's pretty easy to see why. For instance, suppose we're talking about hanging out at a local bar. Does not wanting to go by yourself mean it's a shitty bar?
Halo games offer an extremely strong social couch experience, such that it's not at all weird that that would be the main draw for someone.
Not wanting Halo without split-screen coop doesn't mean that the person thinks it's an individually shit experience; it just means that it's not offering what defines the Halo experience for them, and they'd rather do something else that they enjoy more than single-screen Halo (such as play a different game that offers a strong local coop experience).