I think the point is being missed here... probably becasue folks are not familiar with the phrase "vital need" as it is used in the study of environmental ethics. Something is a "vital need" if it is something that is directly required for an organism's survival (e.g., food, water, shelter). This contrasts to what is called a "peripheral need" or something that is not required for an organism's survival (e.g., sex, entertainment, affluence). It doesn't matter if there are multiple things that can satisfy a particular vital need - the point is that it serves something vital as opposed to peripheral. I'm not suggesting that the many things that satisfy a vital need are "the same" - I'm simply pointing out that eating (whether it's meat or something else) satisfies a vital need, and having sex (particularly with something that isn't a member of one's own species) does not.
When it comes to asking what is ethical, some environmental philosophers have argued that things which sustain vital needs have ethical high ground over those that do not. Thus, the categorical difference between eating meat (a vital need) and having sex with a non-human animal (peripheral need) becomes important. Another element that comes into play here: when an organism satisfies peripheral needs at the expense of the vital needs of another organism, that is a good sign that the behavior is unethical. Hunting for sport would fall into that category - a human is killing another creature to serve the peripheral need of the joy of the hunt or a trophy.
As an aside, I suppose the major problem I have with the "vegetarian high ground" argument is that it disregards the needs of plants. As a lover of plants, that just really grinds me the wrong way. There's no getting around the fact that humans must kill to live. As far as I'm concerned, killing one type of organism is not "more ethical" than killing any other type of organism. What makes something more or less ethical to me is how the creature was treated during its life. And. on both the animal and the plant side, industrial agriculture treats organisms rather poorly.