There are nice people on reddit, of course. You might be able to say that some subcommunity of reddit maximizes `lambda subcommunity: f(subcommunity.size) * g(

There are nice people on reddit, of course. You might be able to say that some subcommunity of reddit maximizes `lambda subcommunity: f(subcommunity.size) * g(subcommity.loveliness)` over all possible subcommunities of all community websites (and for some reasonable weighting functions f and g), but if you're generalizing to the entire reddit community then I can't help thinking you're mistaken.