I think in general it's because CGA is predominately a STEM school. The engineering and technical majors are their bread and butter and there aren't many options otherwise. Because of that, what you'll often hear from people is Gov and Mgt are in many cases fall back majors. If there's a cadet in an engineering major who is really struggling academically, they can make a play to switch to Gov or Mgt as they tend to be much easier majors with less homework. I'm by no means knocking these majors, it's just what most any cadet would tell you. That said, I think the gov and mgt majors take some gentle ribbing all in good fun from their jealous engineering counterparts over their better quality of life. LOL.
That said, Government and Management are great majors, important to the overall mission, and there are plenty of applicants who select those as their first choice because that's legit what they want to study! However, because those majors are partially self populated from internal trickle down, those who apply with those majors are potentially in a much more competitive pool.
My understanding is while it probably happens plenty, there's still a lot of red tape in changing majors. Particularly now that they are divided into 3 separate schools (Engineering & Cyber, Math/Science/Humanities, and Leadership/Government). I've heard it's harder to move outside of your school. You can't just do whatever you want at that place.
Another tidbit, I've heard people say for a period of time, Cyber was hot ticket to choose on your application. My cadet was recently telling me that right now ORDA is getting some attention as 2027 was pretty light on ORDA.