EpicEnergy

Look at the end result, as Rainbow Dash helped make the cheerleading team awesome. That's what I think is one of the main reasons Twilight chose Rainbow, because she knew Rainbow would put awesomeness into the cheerleading team. Another reason is because Fluttershy and Pinkie are phenomenal at buckball and needed to coach the buckball team, so that eliminated those two from the potential cheerleader coaches. Rarity was busy with the outfits which also disqualified her, and she probably would have made the cheerleading team too aesthetic oriented if she was the coach. AJ was open, but she probably would have made the cheerleading team too practical. Twilight herself could have done it, but I think she was too busy with administrative duties and wouldn't have made the cheerleading team as awesome as Rainbow Dash did anyways. Ultimately, I think Twilight choose RD because she was hoping Rainbow would put her energy and awesomeness into the cheerleading team, which is why the end result was an awesome and successful cheerleading performance. Therefore, I think Twilight knew what she was doing when she made this decision, and I also think that this was a right decision. Also, I don't even see anything wrong with Rainbow's attitude towards cheerleading, it makes sense to me - Rainbow loves acting cool and awesome, cheerleading seems too girly for her. She also loves buckball, so that made coaching cheerleaders even more unappealing because Rainbow really wanted to do something else (she initially brought a whole bunch of training gear before she was told of her role because she was wanting and expecting to be a buckball coach). In conclusion, I see Rainbow's attitude towards cheerleading as reasonable.