Any issues with shooting at 1280 x 720?

Another stupid question.  If I always export my video from Premiere at 1280 x 720, is there ANY reason that I should be shooting my footage at 1920 x 1080?

I just got a second camera that will only shoot 29.97 fps at 1280 x 720 and I thought, "hey all I need to do is shoot all my footage at 1280 x 720 since I'm exporting at that resolution anyway.

Do you see any reason not to do this?

Thanks.