Drum corps arranging is generally pretty bland, arrangers generally aren't trained in composition and don't seem to have a ton of knowledge or creativity (the only drum corps arrangements that have really impressed me and come off as interesting are those of Jay Bocook) so you can't really blame them for generic writing.
I think my biggest pet peeve is probably just the fact that pretty much every arranger only writes in three keys, B-flat major, E-flat major and F major, especially for openers. I understand this is done for acoustic reasons, but honestly, if you have a good corps to work with you should be more worried about being a bit more artistic and not just mulling over whether or not a chord is going to be hard to tune or not.
That leads me to another thing, there's a lack of artistry in drum corps arranging in general (how many times does Appalachian Spring have to be played for people to realize that?) The genre in general is a retrogressive one, and whenever a corps comes along which goes against the aesthetic stream, like a Star or a BK, then there is a SEVERE backlash from many, suffice it to say, uneducated peoples from other corps and in the audience.
Sigh, it isn't that hard, man up plz