Tbh, depending on which Beans you're eating, they can be healthier option for you, as opposed to eating carbs/ white flour and sugar, but I will agree that eating beans everyday for 2 weeks straight with nothing else introduced, is probably not as healthy some might think it is - cuz with everything, one is supposed to eat different foods in moderation, rather than in excess. For some people, beans can cause digestive gas and floating effects- depending on how much they eat.
Although I have nothing against Baked Beans or Red Kidney Beans or Green String Beans (which is even more healthy for you), cuz I grew up eating these since I was a kid, I can't see myself eating them everyday for 2 weeks, cooked the same way each time for each meal - cuz I would get bored. Additionally, my go to bean of choice is that of the Black Bean. I can eat half a small can of it in soup and I'll be full for like the entire day, cuz it's just that heavy in fiber content - which is good for the gut. Unfortunately I can't always afford it, so Baked Beans, Red Beans or freshly picked String Beans are often a cheaper substitution, though it's not as effective at keeping me full for the entire day.