Is it because you think people derive much less fun from it than they do from eating meat?

I was actually thinking of “fun” in a narrower sense (I was going to say “the hell of it” instead, and I'm not sure why I changed my mind); so I guess that

you see some qualitative distinction between the two

is kind-of right, even though, as someone said, a qualitative difference is just a sufficiently large quantitative difference (which translates to LWese as “SPECKS is worse than TORTURE”). By using “Fun” is a more general sense (note the capital F)... [thinks about it] yes, they derive much less Fun from the former than from the latter per animal killed, but I don't think that one bug should count for as much as one cow, so... [thinks a little more about it] I dunno whether people derive that much less Fun from the former than from the latter per unit ‘moral value’.

(Another difference beside levels of Fun is that, as Robin Hanson points out (though I disagree with pretty much everything else in that essay), is that the livestock killed for food are usually animals that if you hadn't been going to kill them for food would have never existed in the first place. This doesn't apply to game, and indeed I consider hunting to be more similar to killing animals for the hell of it than to killing animals for food, even if you do eat them.)