Well, as far as my observations go, it comes down to the old adage, "once bitten, twice shy." We used to have a fish tank back in Denver, when I was very young, and again later when I was older but still at that stage of childhood that meant I liked having a pet, but hated taking care of it. So it was usually mom taking care of said tanks, and she hated the workload of it. So she doesn't want me to get a tank in my room, either for fear I'll mistreat it, or for fear it will make my room and the house smelly and damp, or for whatever other reasons.
Space, though, is the other issue now. Since I'd like to cycle a tank, and a 2.5 tank is difficult to cycle, it would be more beneficial and advantageous to trade it for a 5 gallon.That was a nice, tiny little detail I didn't learn until tonight that would've been useful to know earlier, before I bought anything specifically for the 2.5. But I don't have anyplace in my room that will fit a 5 gallon glass rectangle tank and allow easy access. (I would if I didn't have those shelves on the wall, but I can't move them. bah.) And I say that kind of tank specifically, because its cheapest for me; if I get a kit tank with different dimensions, then I'm paying extra for a filter thats probably too strong and won't be used.