This topic gets touched on quite a bit here and elsewhere on the site. The topic comes up in "best burrito threads" and "what is a mission burrito" threads and in a few other places.
But -- unless I'm not searching long and hard enough -- I've never seen a definitive thread on just this topic. If there has been, maybe it's old so it's time for a new one.
Here's my take:
I do eat rice in burritos. In fact, I used to always think that rice always was an ingredient in a burrito. Then I read in a review of a restaurant (I think it was Jonathan Gold in LA Weekly, though maybe not) that rice is not really a traditional burrito ingredient. Burritos were more a smear of beans and maybe whatever beef, pork or chicken was leftover from the night before. I'm not a traditionalist at all, "authentic" is one of the least meaningful qualities for me, but I am an improviser and the realization that a great burrito is a tortilla, beans and some leftovers hit home. I don't even know if it is true. (I'm also a sandwich improviser -- odd combinations of whatever meats, condiments and breads I have around make for the best sandwiches of all.)
So, I started ordering my burritos that way. Shrimp burrito, no rice. Chicken burrito, no rice. Sometimes just chicken, or just chili colorado.
And I'm finding that I really do prefer the simpler burritos. No rice (and also no lettuce, no sour cream, no pico de gallo inside). Just some beans, some great meat and some salsa that I add with each bite.
Which is not to say that I won't eat a burrito with rice. I might eat a bean and rice burrito if the mood strikes. But what I've found is that the rice adds more as a consistency ingredient than a flavor ingredient. The rice acts as a stabilizer, sort of like gravel in cement (the beans) and also helps to soak up some of the juice from the meat. A meat and bean burrito can be a little limp and a little drippy. Also, rice-less burritos are smaller.
Rice in a burrito is very common, almost ubiquitous. I suspect that most burritos have rice and that most prefer then that way. Still, I'm curious:
Rice in a burrito: Yay or nay?