The thought of having to expand my nut-consumption in order to get the adequate protein intake doesn't sound fun. I've never been fond of nuts. And you can only eat so much cheese and milk.
It wasn't until I became pregnant that I truly believed I could eat vegetarian. This was because I have not craved meat whatsoever. During my first trimester, it tasted bad and made me feel sick. During my second trimester, it didn't make me sick anymore, and I ate it every once in a while, but I still found myself skipping the bar-b-q chicken to eat the potato salad, cole slaw and beans. Every time I visit a blog that encourages people to eat healthily and naturally (ahem, Happy Foody), it makes me want to throw out my store-bought bread, margarine, canned veggies, and hormone-injected meat. Alas, I will never succeed.