Texans don't put beans in chili because beans are filler. The implication seems to be that they don't add anything to the flavor of the chili other than to stretch it further. Basically, every bean in a chili could have been a chunk of beef. I don't know if I necessarily agree that beans don't add anything to chili, but they are definitely filler and while I have never said the phrase "this chili has too much meat", I have certainly said "this chili has too many beans". To make matters worse, people who are new to chilimaking see 'chili beans' in the bean aisle and assume that chili is named after the beans rather than the seasoning combination of cumin and dried chiles. This tends to result in bean-heavy, underseasoned and shitty chili. ftr: chili beans are just pinto beans soaked in cumin and chile powder. The more you know.
I usually go one pound of beans per gallon of chili, and I greatly prefer Kidneys and Black Beans over any other type. If you get too crazy with variety you'll end up with A: beans that have no goddamn place in chili (Great northern beans, butterbeans, chickpeas, etc) , B: probably shitty pinto beans and C: a dish that tastes more like beans than goddamn chili. Chili should be showcasing the meat you're using and the flavor of the chiles, not the beans you picked out, so keep that in mind.
edit: oh yeah RE: vegetarian chili
please don't