As for getting a music teaching job, they (some employers) often like to see drum corps experience (some employers will even say top 12 experience) if you're applying for a HS position that has a marching band. I know many educators who did not march corps, who have landed jobs at some amazing programs, and are doing a great job. You don't need to march corps to fill that space on a resume. Heck, I didn't march with a top 12 corps, and I'm still a successful educator, because of what I learned in many arenas.
I marched two seasons, met great people who I am still in touch with, I learned some useful pedagogy, but I didn't consider it to be the end all be all. As a clarinetist, I'm also now a great low brass specialist when I have to be. Drum corps was worth it for me. I'd march again if I had it to do over again.