It's personal preference I suppose, and economic viability. I workout, alot. Thus my protein intake is higher than the average persons, or at least it should be higher, though most people eat far too much(in general) and frankly thats why he have tons of fat people in america, pun intended. I eat some vegetables obviously, I was being a bit silly with the biscuits and gravy post, but I've tried going vegetarian once or twice and I can honestly say the experience was close to what the op described. And no before you ask I was not malnourished in any sense of the word before or after, it's simply that I have a high metabolism which I've worked hard to develop, and it requires a fairly ridiculous amount of vegetables that contain protein to compensate for what I can get from reasonable amount of meat. Beans for instance are a regular part of my diet, they're cheap, they contain a reasonable amount of protein and fiber, and go with quite alot of other things that I like, eggs beans and whatever meat for breakfast for instance or the obvious burrito type stuff.
In general while most "health" oriented people seem to think that one's health is mostly a function of what you eat, I hate to tell you this folks but pro meat anti meat whatever, you're wrong, period. Your physical activity accounts for nearly 75% of that health, food whatever the food typically only accounts for around 25%. If you took a meat eater and a veggie eater, gave them the same job sitting at a desk all day, but the meat eater hits the gym for an hour each evening before dinner, the meat eater (barring genetic predisposition to some disease or another) will end up healthier. Likewise if you send the veggie eater to the gym in the same fashion the veggie eater will be the healthier of the two. I know this to be the case with men factually, though it may be a bit different for womens bodies as they have a different set of baseline requirements, but overall I'd imagine it holds true with a bit of tweaking there as well.
So again I say, it's preference. I enjoy a good steak, a good burger, or the aforementioned biscuits and gravy, but I also enjoy pushing myself doing resistance exercises, and doing cardio and it balances out just fine.